| 1. |
- Serikov, V. V., et al.
(författare)
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Formation of solid solutions of gallium in Fe-Cr and Fe-Co alloys : Mossbauer studies and first-principles calculations
- 2014
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 614, s. 297-304
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Tidskriftsartikel (refereegranskat)abstract
- Investigation of Ga influence on the structure of Fe-Cr and Fe-Co alloys was performed with the use of Mossbauer spectroscopy and X-ray diffraction methods. The experimental results are compared with results of first-principles calculations of the mixing and solubility energies for Ga in an Fe-X (X = Co, Cr) alloy both in ferromagnetic and paramagnetic states. It is shown that Ga mainly goes into the solid solutions of the base alloys. In the alloys of the Fe-Cr system, doping with Ga handicaps the decomposition of solid solutions, observed in the binary alloys, and increases its stability. In the alloys with Co, Ga also favors the uniformity of solid solutions. The results of the first-principles calculations testify in favor of a preferable dissolution of Ga in the FeCo regions of a multicomponent structure rather than FeCr regions, both types of regions being in the ferromagnetic state at the temperature of annealing. The analysis of Mossbauer experiments gives some grounds to conclude that if, owing to liquation, clusterization, or initial stages of phase separation, there exist regions enriched in iron, some amount of Ga atoms prefer to enter the nearest surroundings of iron atoms, thus forming binary Fe-Ga regions (or phases).
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| 2. |
- Glazyrin, K., et al.
(författare)
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Importance of Correlation Effects in hcp Iron Revealed by a Pressure-Induced Electronic Topological Transition
- 2013
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 110:11, s. 117206-
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Tidskriftsartikel (refereegranskat)abstract
- We discover that hcp phases of Fe and Fe0.9Ni0.1 undergo an electronic topological transition at pressures of about 40 GPa. This topological change of the Fermi surface manifests itself through anomalous behavior of the Debye sound velocity, c/a lattice parameter ratio, and Mossbauer center shift observed in our experiments. First-principles simulations within the dynamic mean field approach demonstrate that the transition is induced by many-electron effects. It is absent in one-electron calculations and represents a clear signature of correlation effects in hcp Fe.
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| 3. |
- Bogdanov, V. I., et al.
(författare)
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Chemical and deformational interactions in solid solution of carbon in nickel
- 2012
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Ingår i: Physics of metals and metallography. - 0031-918X .- 1555-6190. ; 113:9, s. 831-835
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Tidskriftsartikel (refereegranskat)abstract
- A first-principles stuy of ordering phenomena in hcp interstitial solid solutions of oxygen and nitrogen in Ti, Zr and Hf has demonstrated that the dominant contributions to the interaction energy of interstitial atoms are of chemical nature; thus, it is necessary to modify the previously established concepts about the priority role of deformational interactions in interstitial solutions. We have continued studies of the role of chemical and deformational interactions of interstitial atoms by the example of solid solutions of carbon in nickel. The results obtained also confirm a significant role of chemical interactions between carbon atoms in these solid solutions. The results were compared with the experimental data on the enthalpy of carbon dissolution in nickel and on the coefficient of solutal expansion of the lattice.
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| 4. |
- Bogdanov, V. I., et al.
(författare)
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First-principles investigations of interatomic interactions in Ni3Al alloyed by interstitial and substitutional impurities
- 2013
-
Ingår i: Physics of metals and metallography. - 0031-918X .- 1555-6190. ; 114:3, s. 191-196
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Tidskriftsartikel (refereegranskat)abstract
- First-principles calculations of the total energy of interstitial and substitutional solid solutions in intermetallic compound Ni3Al were performed based on methods using Vienna ab-initio simulation package (VASP). The results of the calculations for interstitial solutions of carbon in Ni3Al confirmed the priority role of chemical interactions over deformational ones for the nearest neighbors. We attempted to use first-principles methods of calculation of the deformation interaction and continuum approaching in the theory of solutions to calculate coefficients of the concentration changes of the lattice spacing. Comparison of the calculation results with experimental data of substitutional impurities in Ni3Al has shown that the proposed method can aid in the study of the distribution of impurity atoms on the sublattices of the ordered phases, intermetallic compounds. We have proposed a method of calculating the partial molar volume of impurity in interstitial solid solutions.
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| 5. |
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| 6. |
- Gorbatov, O. I., et al.
(författare)
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Role of Magnetism in the Formation of a Short-Range Order in Iron-Silicon Alloys
- 2011
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Ingår i: Journal of Experimental and Theoretical Physics. - 1063-7761 .- 1090-6509. ; 112:5, s. 848-859
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Tidskriftsartikel (refereegranskat)abstract
- The formation of a short-range order in soft magnetic Fe-Si alloys depending on the annealing temperature has been investigated theoretically and experimentally. The B2-type short-range order has been observed in samples quenched from temperatures T > T(C) (where T(C) is the Curie temperature) with the content c(Si) close to the boundary of the two-phase region. Annealing at temperatures T < T(C) for the content c(Si) >= 0.08 leads to an increase in the fraction of regions with the D0(3)-type short-range order. The mechanism of the formation of the short-range order in Fe-Si solid solutions has been analyzed by the Monte Carlo simulation with the ab initio calculated interatomic interaction parameters. It has been shown that the energy of the effective Si-Si interaction in bcc iron strongly depends on the magnetic state of the matrix. As a result, the B2-type short-range order is formed at T > T(C) and is fixed at quenching, whereas the D0(3)-type short-range order is equilibrium in the ferromagnetic state. The results reveal the decisive role of magnetism in the formation of the short-range order in Fe-Si alloys and allow the explanation of the observed structural features of the alloys depending on the composition and temperature.
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| 7. |
- Ruban, Andrei V., et al.
(författare)
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First-principles study of point defects in Ni3Al
- 2014
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 94:1, s. 20-34
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Tidskriftsartikel (refereegranskat)abstract
- The energetics and structural properties of native, substitutional and interstitial defects in Ni3Al have been investigated by first-principles methods. In particular, we have determined the formation energies of composition conserving defects and established that the so-called penta defect, which consists of four vacancies on Ni sublattice and Ni antisite on the Al sublattice, is the main source of vacancies in Ni3Al. We show that this is due to the strong Ni-site preference of vacancies in Ni3Al. We have also calculated the site substitution behaviour of Cu, Pd, Pt, Si, Ti, Cr, V, Nb, Ta and Mo and their effect on the concentration expansion coefficient. We show the latter information can used for an indirect estimate of the site substitution behaviour of the alloying elements. The solution energy of carbon and its effect on the lattice constant of Ni3Al have been obtained in the dilute limit in the first-principles calculations. We have also determined the chemical and strain-induced carbon-carbon interactions in the interstitial positions of Ni3Al. These interactions have been subsequently used in the statistical thermodynamic simulations of carbon ordering in Ni3Al.
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| 8. |
- Blanter, M. S., et al.
(författare)
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Ab initio Based O-O Investigation and the Snoek Relaxation in Nb-O
- 2012
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Ingår i: Diffusion and Defect Data Pt.B. - : Trans Tech Publications Inc.. - 9783037853382 ; , s. 63-68
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Konferensbidrag (refereegranskat)abstract
- It is common knowledge that interstitial-interstitial interaction influence on the Snoek relaxation. We used a computer simulation of this effect in the Nb-O alloy to test the adequacy of various models of the O-O interaction and clarify the mechanism of this effect The energy calculations in the first twelve coordination shells have been performed by the projector augmentedwave (PAW) method as implemented in the Vienna ab initio simulation package (VASP). The energies have been calculated in different ways which vary in the method of determination the energy of non-interacting O-O pairs. The energies calculated on the various variants are similar but in one case there is O-O repulsion in all first twelve coordination shells, whereas in another one can see attraction in four of twelve shells. Internal friction Q -1 was calculated as a sum of the contributions from individual interstitial atoms in different environments, each of which being assumed to be the Debye function. It is assumed that long-range interaction of oxygen atoms affects the distribution of these atoms and the energy of each interstitial atom in the octahedral interstices before a jump and after a jump. The Monte Carlo method is used for simulating short-range order of interstitial atoms and for calculating values of energy changes. Comparison of the calculated temperature and concentration dependence of the Snoek peak with the published data showed that the PAW supercell calculation of the O-O interactions in Nb describes the behavior of the interstitial solid solution adequately. It proves also that the impact of interstitial atom concentration on the Snoek relaxation is connected to the mutual attraction of these atoms.
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| 9. |
- Blanter, M. S., et al.
(författare)
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Interstitial-interstitial interactions in bcc VB group metals : Ab initio calculations
- 2013
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Ingår i: Journal of Physics and Chemistry of Solids. - : Elsevier BV. - 0022-3697 .- 1879-2553. ; 74:5, s. 716-722
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Tidskriftsartikel (refereegranskat)abstract
- Chemical and strain-induced interactions of oxygen and nitrogen interstitials in bcc V and Ta have been obtained for the first 12 coordination shells in the supercell first-principles calculations by the Viena ab initio simulation package (VASP). It is shown that the chemical interactions are dominating at the first several coordination shells while the strain-induced interactions become important at more distant coordination shells. The latter are in reasonable agreement with the earlier results of a microscopic phenomenological Krivoglaz-Kanzaki-Khachaturyan model (KKKM). The obtained interstitial-interstitial interactions have been used in calculations of the concentration dependence of the oxygen Snoek peak, which is in good agreement with the existing experimental data.
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| 10. |
- Blanter, M. S., et al.
(författare)
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Ordering in V-O and V-N solid solutions : Computer simulation
- 2014
-
Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 78:10, s. 1030-1034
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Tidskriftsartikel (refereegranskat)abstract
- The atomic structures of interstitial solid solutions O and N in V at relatively low concentrations O(N)/V = 1/16 or 1/8 are calculated using the Monte Carlo method. A combined model of long-range interaction between interstitial atoms is employed. The first 12 shells contain ab initio energies and the energies in shells 13–18 are calculated on the basis of a phenomenological model of deformation interaction. The ordered solid solutions are long-period structures with body-centered tetragonal crystal lattices and tetragonality c/a < 1.
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| 11. |
- Blanter, M. S., et al.
(författare)
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Strain-induced interaction of interstitials in IVA group hcp metals
- 2010
-
Ingår i: Journal of Physics and Chemistry of Solids. - : Elsevier BV. - 0022-3697 .- 1879-2553. ; 71:10, s. 1416-1420
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Tidskriftsartikel (refereegranskat)abstract
- Strain-induced (elastic) interactions of oxygen, nitrogen and carbon atoms in IVA group metals, alpha-Ti, Zr, and -Hf, are calculated in the framework of the microscopic Krivoglaz-Kanzaki-Khachaturyan theory. The experimental elastic constants, lattice spacing of the host metal, and concentration expansion coefficients are used as the input numerical parameters. The resulting interactions are stronger in a-Ti than in alpha-Zr and alpha-Hf. A comparative analysis of interactions in the hcp IVA group metals with those in bcc and fcc solid solutions reveals the crystal structure effect. In general, the strain-induced interactions of O, N, and C in hcp IVA group metals are weaker than in bcc solid solutions and are stronger than in fcc solid solutions.
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| 12. |
- Dmitriev, V. V., et al.
(författare)
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Ab initio based investigation of interstitial interactions and Snoek relaxation in Nb-O
- 2012
-
Ingår i: Journal of Physics and Chemistry of Solids. - : Elsevier BV. - 0022-3697 .- 1879-2553. ; 73:2, s. 182-187
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Tidskriftsartikel (refereegranskat)abstract
- Chemical and strain-induced effective pair interactions of interstitial oxygen atoms in bcc Nb have been determined in supercell first-principles calculations using Vienna ab initio simulation package (VASP). The strain-induced interactions are in reasonable agreement with those obtained earlier within a phenomenological microscopic Krivoglaz-Kanzaki-Khachaturyan model (KKKM). At the same time, the chemical interactions, which have been considered to be small in earlier theoretical considerations, turned out to be dominating at the first several coordination shells. The obtained interactions have been used in calculations of the concentration- and temperature-dependence of the internal friction Snoek peak. The theoretical results are found to be in good agreement with the existing experimental data.
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| 13. |
- Dmitriev, V. V., et al.
(författare)
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Interaction of interstitial nitrogen atoms in Nb : Ab initio calculations
- 2012
-
Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 76:1, s. 1-6
-
Tidskriftsartikel (refereegranskat)abstract
- Ab initio calculations of pair nitrogen interstitials interaction in the first 12 coordination shells of a Nb crystal lattice are performed using the Vienna ab initio simulation package (VASP), and chemical and strain-induced contributions are analyzed. It is shown that rapidly decreasing chemical repulsion prevails in the nearest coordination shells, whereas strain-induced (elastic) interaction makes the main contribution in more distant shells.
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| 14. |
- Razumovskiy, Vsevolod I., 1985-, et al.
(författare)
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Effect of Alloying Elements and Impurities on Interface properties in Aluminum Alloys
- 2011
-
Ingår i: Physics of the solid state. - 1063-7834 .- 1090-6460. ; 53:11, s. 2189-2193
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Tidskriftsartikel (refereegranskat)abstract
- The segregation energies of B, Si, P, Cr, Ni, Zr, and Mg on the special grain boundary (GB) Σ5 (210)[100] and on the open (210) surface of aluminum have been determined and the GB splitting energy has been calculated by the density functional theory methods. It has been shown that all elements listed above enrich the GB; for B, Si, P, Cr, Ni and Zr, Mg, interstitial and substitutional sites are preferred, respectively. The effect of alloying elements on the GB binding has been estimated using the parameter η equal to the change in the fracture work of the aluminum GB when adding alloying element atoms. From the viewpoint of strengthening the GB binding forces, Zr, Cr, Ni, and Mg are efficient, Si and B are neutral and phosphorus weakens GBs.
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| 15. |
- Abrikosov, I. A., et al.
(författare)
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Multiscale approach to theoretical simulations of materials for nuclear energy applications : Fe-Cr and Zr-based alloys
- 2013
-
Ingår i: Advances in materials for nuclear energy. - : Materials Research Society. - 9781605114910 ; , s. 3-14
-
Konferensbidrag (refereegranskat)abstract
- We review basic ideas behind state-of-the-art techniques for first-principles theoretical simulations of the phase stabilities and properties of alloys. We concentrate on methods that allow for an efficient treatment of compositional and thermal disorder effects. In particular, we present novel approach to evaluate free energy for strongly anharmonic systems. Theoretical tools are then employed in studies of two materials systems relevant for nuclear energy applications: Fe-Cr and Zr-based alloys. In particular, we investigate the effect of hydrostatic pressure and multicomponent alloying on the mixing enthalpy of Fe-Cr alloys, and show that in the ferromagnetic state both of them reduce the alloy stability at low Cr concentration. For Zr-Nb alloys, we demonstrate how microscopic parameters calculated from first-principles can be used in higher-level models.
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| 16. |
- Gorbatov, Oleg I., et al.
(författare)
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Effect of magnetism on the solubility of 3d elements in BCC iron : Results of first-principle investigations
- 2013
-
Ingår i: Physics of metals and metallography. - 0031-918X .- 1555-6190. ; 114:8, s. 642-653
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Tidskriftsartikel (refereegranskat)abstract
- The methods of quantum-mechanical simulation have been used to study alloys of bcc iron with 3d transition metals in the ferromagnetic and paramagnetic states. It has been shown that the main factor that determines the solubility of the 3d elements is their electronic structure. The energy of the solution, mixing, and effective interatomic interactions vary regularly depending on the position of the element in the Periodic Table and on the magnetic state of the matrix. In some cases, depending on the magnetic state, changes in these quantities lead to the violation of the Hume-Rothery rules that determine the solubility of substitutional elements in alloys. The results obtained help us to understand the microscopic mechanisms that determine the solubility of alloying elements and their effect on the phase stability and structural state of steels.
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| 17. |
- Pourovskii, L. V., et al.
(författare)
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Electronic properties and magnetism of iron at the Earth's inner core conditions
- 2013
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 87:11, s. 115130-
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Tidskriftsartikel (refereegranskat)abstract
- We employ state-of-the-art ab initio simulations within the dynamical mean-field theory to study three likely phases of iron (hcp, fcc, and bcc) at the Earth's core conditions. We demonstrate that the correction to the electronic free energy due to correlations can be significant for the relative stability of the phases. The strongest effect is observed in bcc Fe, which shows a non-Fermi-liquid behavior, and where a Curie-Weiss behavior of the uniform susceptibility hints at a local magnetic moment still existing at 5800 K and 300 GPa. We predict that all three structures have sufficiently high magnetic susceptibility to stabilize the geodynamo.
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| 18. |
- Razumovskiy, Vsevolod I., et al.
(författare)
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The effect of alloying elements on grain boundary and bulk cohesion in aluminum alloys : An ab initio study
- 2011
-
Ingår i: Scripta Materialia. - : Elsevier BV. - 1359-6462 .- 1872-8456. ; 65:10, s. 926-929
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Tidskriftsartikel (refereegranskat)abstract
- The effect of B, Si, P, Cr, Ni, Zr and Mg impurities on cohesive properties of Al and its special grain boundary (GB) Sigma 5 (2 1 0) [1 0 0], as well as their segregation behavior at the GB and (2 1 0) surface are studied from first principles. Our analysis determines Ni to be the best and P the worst alloying elements in regard to the overall resistance to decohesion of Al alloys.
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| 19. |
- Razumovskiy, Vsevolod I., 1985-, et al.
(författare)
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The influence of alloying elements on grain boundary and bulk cohesion in aluminum all : Ab initio study
- 2012
-
Ingår i: Thermec 2011 Supplement. - : Trans Tech Publications Inc.. - 9783037853047 ; , s. 417-422
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Konferensbidrag (refereegranskat)abstract
- The effect of B, Si, P, Cr, Ni, Zr and Mg on cohesive properties of Al and the specialgrain boundary (GB) Σ5 (210)[100], as well as their segregation behavior at the GB and the (210)surface are studied by first principles method. The analysis of these parameters allows us to singleout Ni as the best and phosphorus as the worst interatomic bond strengthening alloying elements.
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| 20. |
- Reyes-Huamantinco, Andrei, et al.
(författare)
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Stacking-fault energy and anti-Invar effect in Fe-Mn alloy from first principles
- 2012
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 86:6, s. 060201-
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Tidskriftsartikel (refereegranskat)abstract
- Based on state-of-the-art density-functional-theory methods we calculate the stacking-fault energy of the prototypical high-Mn steel Fe-22.5 at% Mn between 300 and 800 K. We estimate magnetic thermal excitations by considering longitudinal spin fluctuations. Our results demonstrate that the interplay between the magnetic excitations and the thermal lattice expansion is the main factor determining the anti-Invar effect, the hcp-fcc transformation temperature, and the stacking-fault energy, all of which are in good agreement with measurements.
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| 21. |
- Ruban, Andrei, et al.
(författare)
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Ab initio based investigation of the oxygen and nitrogen interstitial ordering in hcp Hf, Zr, and Ti : An ab initio study
- 2010
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 82:13, s. 134110-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the ordering of oxygen and nitrogen interstitials in hcp Zr, Hf, and Ti using the corresponding oxygen-oxygen and nitrogen-nitrogen interactions obtained in the state-of-the-art first-principles calculations. Two main contributions, chemical and strain induced, to the interstitial-interstitial interactions are obtained by different techniques. We find that there is the strong repulsion between interstitial atoms at the nearest-and next-nearest-neighbor coordination shells, which is solely determined by the chemical interaction determined on a fixed ideal lattice, while both contributions are important for more distant coordination shells. The Monte Carlo simulations reveal the existence of three stoichiometric compositions, MeI1/6, MeI1/3, and MeI1/2, for the ground-state structures of interstitials, having different ordering types. Our results for the structures of oxygen interstitials are in good agreement with existing experimental data for the Ti and Hf alloys. In the case of Zr-O interstitial alloys, we correctly predict the general type of ordering, although the detailed structure is at variance the experimental observations. The ordering transition temperatures in some cases are overestimated by a factor of 2. We also predict the ordering type of nitrogen interstitials in hcp Ti, Zr, and Hf, which are similar to those in the case of oxygen interstitials.
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| 22. |
- Ruban, Andrei V., et al.
(författare)
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Impact of magnetism on Fe under Earth's core conditions
- 2013
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 87:1, s. 014405-
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Tidskriftsartikel (refereegranskat)abstract
- Using a microscopic phenomenological model for longitudinal spin fluctuations (LSFs) based on density functional theory calculations, we demonstrate that under the Earth's core conditions (P approximate to 360 GPa, T approximate to 6000 K), Fe acquires substantial local magnetic moment, up to 1.3 mu(B), for different crystal structure modifications. We demonstrate that the LSFs produce a substantial effect on the magnetic and thermodynamic properties of iron, in particular, its equilibrium volume under solid Earth's core conditions.
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| 23. |
- Alling, Björn, 1980-, et al.
(författare)
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A unified cluster expansion method applied to the configurational thermodynamics of cubic TiAlN
- 2011
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 83:10, s. 104203-
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Tidskriftsartikel (refereegranskat)abstract
- We use a study of the cubic Ti1−xAlxN system to illustrate a practical way of combining the major methodologies within alloy theory, the Connolly-Williams cluster expansion and the generalized perturbation method, in order to solve difficult alloy problems. The configurational, concentration dependent, Hamiltonian is separated into a fixed-lattice and a local lattice relaxation part. The effective cluster interactions of the first part is obtained primarily with a GPM-based approach while the later is obtained using cluster expansion. In our case the impact on the isostructural phase diagram of considering short range clustering beyond the mean field approximation, obtained from the mixing enthalpy and entropy of the random alloy, is rather small, especially in the composition region x ≤ 0.66, within reach of thin film growth techniques.
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| 24. |
- Engelke, M., et al.
(författare)
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Near-surface microstructure of Ni-23 at. % Pt : Grazing incidence diffraction and first-principles calculations
- 2010
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 81:5, s. 054205-
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Tidskriftsartikel (refereegranskat)abstract
- Diffuse x-ray scattering under grazing incidence was measured of a Ni-23.2 at. % Pt(110) surface at 923 K. The modulation of in-plane and out-of-plane scattering is characterized by the maxima in short-range order scattering located at positions of the X type (as for the bulk microstructure). The Warren-Cowley short-range order parameters from diffuse scattering are in good agreement with theoretical simulations based on bulk effective pair interaction parameters from first-principles theory. The nearest-neighbor interaction parameter is dominant also when determined from short-range order scattering. Its value is larger than for the bulk microstructure of Pt-rich alloys, what might reflect the difference in composition and is not compellingly due to the near-surface microstructure. Allowing for the presence of a tetragonal site occupation, indications for a segregation profile are weak in diffuse scattering and hardly resolvable for the Warren-Cowley short-range order parameters. This is consistent with the findings for layer-resolved short-range order parameters from theory. Theoretical simulations also demonstrated that the strong Ni enrichment of the surface layer has the same origin as the segregation reversal for the (110) surface in the case of Ni-50 at. % Pt.
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| 25. |
- Gorbatov, O. I., et al.
(författare)
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Dependence of vacancy-solute interactions on magnetic state in dilute iron-based alloys
- 2011
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Ingår i: Solid-Solid Phase Transformations in Inorganic Materials. - Zurich-Durnten, Switzerland : TRANS TECH PUBLICATIONS. ; , s. 979-984
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Konferensbidrag (refereegranskat)abstract
- Vacancy-solute interactions play a crucial role in diffusion-controlled phase transformations, such as ordering or decomposition, which occur in alloys under heat treatment or under irradiation. The knowledge of these interactions is important for predicting long-term behavior of nuclear materials (such as reactor steels and nuclear-waste containers) under irradiation, as well as for advancing our general understanding of kinetic processes in alloys. Using first-principles calculations based on density functional theory and employing the locally self-consistent Green’s function technique, we develop a database of vacancy-solute interactions in dilute alloys of bcc Fe with 3p (Al, Si, P, S), 3d (Ti – Cu), and 4d (Nb – Ag) elements. Interactions within the first two coordination shells have been computed in the ferromagnetic state as well as in the paramagnetic (disordered local moment) state of the iron matrix. Magnetism is found to have a very strong effect on the vacancy-solute interactions.
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| 26. |
- Gorbatov, O. I., et al.
(författare)
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Effect of magnetism on short-range order formation in Fe-Si and Fe-Al alloys
- 2011
-
Ingår i: International Conference on Solid-Solid Phase Transformations in Inorganic Materials, PTM 2010. - 9783037851432 ; , s. 618-623
-
Konferensbidrag (refereegranskat)abstract
- Short-range order formation in dilute Fe-Si and Fe-Al alloys has been investigated by statistical Monte Carlo simulations with effective interactions deduced from first principles calculations for different magnetic structures of bcc Fe. We find that the variation of the magnetic order from ferromagnetic to paramagnetic leads to significant changes in effective cluster interactions and, as follow, in short-range order parameters of alloys. It is shown in agreement with experiment the B2 type short-range order is formed above the Curie temperature, TC, while the D03 type short-range order is preferred below TC.
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| 27. |
- Gorbatov, Oleg I., et al.
(författare)
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Role of magnetism in Cu precipitation in alpha-Fe
- 2013
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 88:17, s. 174113-
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Tidskriftsartikel (refereegranskat)abstract
- The temperature-dependent solubility of Cu in alpha-Fe and initial stages of Cu precipitation are investigated in first-principles calculations and statistical thermodynamic and kinetic modeling based on ab initio effective interactions. We demonstrate that the weakening of the phase separation tendency with increasing temperature, especially close to the magnetic phase transition, is related to the strong dependence of the "chemical" interactions on the global magnetic state. At the same time, our calculations demonstrate that the vibrational contribution obtained in the quasiharmonic approximation is relatively small for temperatures near the Curie point. The results of Monte Carlo simulations of Cu solubility and clustering are in good agreement with experimental data.
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| 28. |
- Gorbatov, O. I., et al.
(författare)
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Vacancy-solute interactions in ferromagnetic and paramagnetic bcc iron : Ab initio calculations
- 2011
-
Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 419:1-3, s. 248-255
-
Tidskriftsartikel (refereegranskat)abstract
- Vacancy-solute interactions play a crucial role in diffusion-controlled processes, such as ordering or decomposition, which occur in alloys under heat treatment or under irradiation. Detailed knowledge of these interactions is important for predicting long-term behavior of nuclear materials (such as reactor steels and nuclear-waste containers) as well as for advancing our general understanding of kinetic processes in alloys. Using first-principles calculations based on the density functional theory and employing the locally self-consistent Green's function technique, we develop a database of vacancy-solute interactions in dilute alloys of bcc Fe with 3p (Al, Si, P, S), 3d (Sc-Cu), and 4d (Y-Ag) elements. Unrelaxed interactions within the first three coordination shells have been computed in the ferromagnetic state as well as in the paramagnetic (disordered local moment) state of the iron matrix. Magnetism is found to have a strong effect on the vacancy-solute interactions. Implications of the obtained results for interpreting the effects of vacancy trapping and enhanced impurity diffusion are discussed.
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| 29. |
- Kabliman, Evgeniya, et al.
(författare)
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Ab initio-based mean-field theory of the site occupation in the Fe-Cr sigma-phase
- 2011
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : AMER PHYSICAL SOC. - 1098-0121 .- 1550-235X. ; 83:9, s. 092201-
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Tidskriftsartikel (refereegranskat)abstract
- An efficient first-principles-based mean-field theory is applied to study the site occupations in the Fe-Cr sigma phase. It is based on the expansion of the total energy of a random alloy close to the equiatomic composition in the paramagnetic state in terms of the effective on-site interactions and takes into account longitudinal spin fluctuations at high temperatures. The calculated site occupation is in very good agreement with the existing experimental data.
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| 30. |
- Kabliman, Evgeniya, et al.
(författare)
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Ab Initio Study of Lattice Site Occupancies in Binary Sigma Phases Using a Single-Site Mean Field Model
- 2012
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 2:3, s. 654-668
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Tidskriftsartikel (refereegranskat)abstract
- The site occupation of binary Fe-Cr, Co-Cr, Re-W and Fe-V sigma phases is studied in the present work with a first-principles-based single-site mean field theory. We show that the alloy components in these systems exhibit similar site preferences except for the Re-W system, where the occupation of two sites is reversed in agreement with previously published works. In case of the FeV sigma phase, for which the size mismatch between the alloy components is large, we also include into our consideration the effect of local lattice relaxations. The obtained results are found in good agreement with the experimental data and previous theoretical studies.
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| 31. |
- Kabliman, Evgeniya, et al.
(författare)
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Configurational thermodynamics of the Fe-Cr sigma phase
- 2011
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 84:18, s. 184206-
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Tidskriftsartikel (refereegranskat)abstract
- Configurational thermodynamics of the Fe-Cr sigma phase is investigated on the basis of an Ising-type configurational Hamiltonian and a single-site mean-field model for the free energy. The parameters of the statistical models are obtained from efficient first-principles calculations using different computational techniques. We demonstrate that the effective pair and multisite interactions in the sigma phase are relatively small, which allows using a simplified model for distributing Fe and Cr atoms among sublattices. We also show that this system exhibits a nontrivial magnetic behavior at high temperatures, which affects the site occupation by Fe and Cr atoms. The structural variation (volume and c/a) that might be present due to neutron irradiation and thermal expansion can lead to an additional atomic redistribution.
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| 32. |
- Landa, A., et al.
(författare)
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Ab initio study of advanced metallic nuclear fuels for fast breeder reactors
- 2012
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Ingår i: Actinides And Nuclear Energy Materials. - : Materials Research Society. - 9781605114217 ; , s. 67-78
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Konferensbidrag (refereegranskat)abstract
- Density-functional formalism is applied to study the ground state properties of γ-U-Zr and γ-U-Mo solid solutions. Calculated heats of formation are compared with CALPHAD assessments. We discuss how the heat of formation in both alloys correlates with the charge transfer between the alloy components. The decomposition curves for γ-based U-Zr and U-Mo solid solutions are derived from Ising-type Monte Carlo simulations. We explore the idea of stabilization of the γ-UZr2 compound against the α-Zr (hcp) structure due to increase of Zr d-band occupancy by the addition of U to Zr. We discuss how the specific behavior of the electronic density of states in the vicinity of the Fermi level promotes the stabilization of the U2Mo compound. The mechanism of possible Am redistribution in the U-Zr and U-Mo fuels is also discussed.
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| 33. |
- Landa, A., et al.
(författare)
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Alloying-driven phase stability in group-VB transition metals under compression
- 2010
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 82:14, s. 144114-
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Tidskriftsartikel (refereegranskat)abstract
- The change in phase stability of group-VB (V, Nb, and Ta) transition metals due to pressure and alloying is explored by means of first-principles electronic-structure calculations. It is shown that under compression stabilization or destabilization of the ground-state body-centered-cubic (bcc) phase of the metal is mainly dictated by the band-structure energy that correlates well with the position of the Kohn anomaly in the transverse-acoustic-phonon mode. The predicted position of the Kohn anomaly in V, Nb, and Ta is found to be in a good agreement with data from the inelastic x-ray or neutron-scattering measurements. In the case of alloying the change in phase stability is defined by the interplay between the band-structure and Madelung energies. We show that band-structure effects determine phase stability when a particular group-VB metal is alloyed with its nearest neighbors within the same d-transition series: the neighbor with less and more d electrons destabilize and stabilize the bcc phase, respectively. When V is alloyed with neighbors of a higher (4d- or 5d-) transition series, both electrostatic Madelung and band-structure energies stabilize the body-centered-cubic phase. The opposite effect (destabilization) happens when Nb or Ta is alloyed with neighbors of the 3d-transition series.
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| 34. |
- Luo, H. B., et al.
(författare)
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Effect of stoichiometry on the magnetocrystalline anisotropy of Fe-Pt and Co-Pt from first-principles calculation
- 2014
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 26:38, s. 386002-
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Tidskriftsartikel (refereegranskat)abstract
- The effect of stoichiometry on magnetocrystalline anisotropy energy (MAE) of Fe1+xPt1-x and Co1+xPt1-x (-0.5 < x < 0.5) is studied by use of first-principles method. The calculated MAEs show maxima at x = 0 for both fully L1(0)-ordered systems. Compared with that, the MAEs of partially L1(0)-ordered systems reduce but their composition dependences do not change, without shift of the maximum MAE to Fe/Co-rich alloy as found in experiment at room temperature. In the off-stoichiometric alloys, the misoccupied Fe/Co and Pt show large MAEs, which is explained by the enhanced in-plane hybridization between Fe/Co and Pt. The composition dependence of the atom-resolved MAE is governed by the varying number of heterogeneous ligands around the atom. The MAE(T)/MAE(0) is discussed based on spontaneous magnetization and Curie temperature, which suggests that the temperature effect may contribute to the discrepancy between calculation and experiment in the composition dependence of MAE.
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| 35. |
- Peil, O. E., et al.
(författare)
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Self-consistent supercell approach to alloys with local environment effects
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 85:16, s. 165140-
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Tidskriftsartikel (refereegranskat)abstract
- We present an efficient and accurate method for calculating electronic structure and related properties of random alloys with a proper treatment of local environment effects. The method is a generalization of the locally self-consistent Green's-function technique for the exact muffin-tin orbital method. An alloy system in the calculations is represented by a supercell with a certain set of atomic-distribution correlation functions. The Green's function for each atom in the supercell is obtained by embedding the cluster of neighboring atoms lying within a local interaction zone (LIZ) into an effective medium and solving the cluster Dyson equation exactly. The key ingredients of the method are locality, which makes it linearly scaling with the number of atoms in the supercell, and coherent-potential self-consistency of the effective medium, which results in a fast convergence of the electronic structure with respect to the LIZ size. To test the performance and accuracy of the method, we apply it to two systems: Fe-rich bcc-FeCr random alloy with and without a short-range order, and a Cr impurity on the Fe surface. Both cases demonstrate the importance of taking into account the local environment effects for correct description of magnetic and bulk properties.
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| 36. |
- Razumovskiy, Vsevolod I., 1985-, et al.
(författare)
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Ab-initio calculations of kinetic properties in ZrC and TiC carbides
- 2011
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Konferensbidrag (refereegranskat)abstract
- Self-diffusion of the metal and carbon atoms in TiC and ZrC carbides is studied by first principles methods. Our calculations yield point defects energies, vacancy jump barriers and diffusion pre-factors in TiC and ZrC. The results are in reasonable agreement with the available experimental data and suggest that the self-diffusion mechanism for metal atoms in these carbides may involve nearest-neighbor vacancy pairs (one metal and one carbon vacancy).
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| 37. |
- Razumovskiy, Vsevolod I., 1985-, et al.
(författare)
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Analysis of the Alloying System in Ni-Base Superalloys Based on Ab Initio Study of Impurity Segregation to Ni Grain Boundary
- 2011
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Ingår i: EURO SUPERALLOYS 2010. - : Trans Tech Publications Inc.. - 9783037851135 ; , s. 192-197
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Konferensbidrag (refereegranskat)abstract
- A new approach to the design of Ni-based polycrystalline superalloys is proposed. It is based on a concept that under given structural conditions, the performance of superalloys is determined by the strength of interatomic bonding both in the bulk and at grain boundaries of material. We characterize the former by the cohesive energy of the bulk alloy, whereas for the latter we employ the work of separation of a representative high angle grain boundary. On the basis of our first principle calculations we suggest Hf and Zr as “minor alloying additions” to Ni-based alloys. Re, on the other hand, appears to be of little importance in polycrystalline alloys.
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| 38. |
- Razumovskiy, Vsevolod I., 1985-, et al.
(författare)
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Effect of temperature on the elastic anisotropy of pure Fe and Fe0.9Cr0.1 random alloy
- 2011
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 107:20
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Tidskriftsartikel (refereegranskat)abstract
- The elastic properties of pure iron and substitutionally disordered 10 at. % Cr Fe-Cr alloy areinvestigated as a function of temperature using first-principles electronic-structure calculations bythe exact muffin-tin orbitals method. The temperature effects on the elastic properties are includedvia the electronic, magnetic, and lattice expansion contributions. We show that the degree ofmagnetic order in both pure iron and Fe90Cr10 alloy mainly determines the dramatic change of theelastic anisotropy of these materials at elevated temperatures. The effect of lattice expansion isfound to be secondary but also very important for quantitative modeling.
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| 39. |
- Razumovskiy, Vsevolod I., et al.
(författare)
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First-principles study of elastic properties of Cr- and Fe-rich Fe-Cr alloys
- 2011
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 84:2
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Tidskriftsartikel (refereegranskat)abstract
- Elastic properties of substitutionally disordered Cr- and Fe-rich Fe-Cr alloys are derived from first-principles calculations using the exact muffin-tin orbitals method and the coherent potential approximation. A peculiarity in the concentration dependence of elastic constants in Fe-rich alloys is demonstrated and related to a change in the Fermi surface topology. Our calculations predict high values for the elastic constants of Cr-rich Fe-Cr alloys, but at the same time show that these alloys could be rather brittle according to the Pugh criterion (the ratio between shear and bulk moduli is calculated to be greater than 0.5).
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| 40. |
- Razumovskiy, Vsevolod I., et al.
(författare)
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Vacancy-cluster mechanism of metal-atom diffusion in substoichiometric carbides
- 2013
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 87:5, s. 054203-
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Tidskriftsartikel (refereegranskat)abstract
- We find, using ab initio atomistic simulations of vacancy-mediated diffusion processes in TiC and ZrC, that a multivacancy self-diffusion mechanism is operative for metal-atom diffusion in substoichiometric carbides. It involves a special type of a stable point defect, a metal vacancy "dressed" in a shell of carbon vacancies. We show that this vacancy cluster is strongly bound and can propagate through the lattice without dissociating.
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| 41. |
- Ruban, Andrei V., et al.
(författare)
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First-principles based thermodynamic model of phase equilibria in bcc Fe-Cr alloys
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 86:17, s. 174111-
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Tidskriftsartikel (refereegranskat)abstract
- A first-principles based thermodynamic model for magnetic alloys is applied to the calculation of the Fe-Cr phase diagram restricted by the bcc structure. The model includes magnetic, electronic, phonon, and local atomic relaxations contributions to the free-energy derived from ab initio calculations. Atomic short-range-order effects are found to be relatively small and they have been neglected in the calculations, assuming that alloys are in the completely random state. In contrast, we have taken into consideration magnetic short-range-order effects, which are found to be very important in particular above the Curie temperature. The calculated phase diagram is in reasonable agreement with the latest CALPHAD assessment. Our calculations reproduce a feature known as a Nishizawa horn for the Fe-rich high-temperature part of the phase diagram.
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| 42. |
- Ruban, Andrei V.
(författare)
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Self-trapping of carbon atoms in alpha '-Fe during the martensitic transformation : A qualitative picture from ab initio calculations
- 2014
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 90:14, s. 144106-
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Tidskriftsartikel (refereegranskat)abstract
- Strain-induced and chemical interactions of interstitial carbon atoms in bcc or alpha-Fe are obtained in first-principles calculations. Subsequent Monte Carlo simulations show that at low temperatures, carbon atoms prefer to occupy at least two different octahedral sublattices, which is due to quite strong attractive interactions of carbon atoms at the corresponding coordination shells. The direct total-energy calculations of one of the obtained ordered structures with composition Fe16C2, show that it is more stable than the predicted earlier structure with the same composition but carbon atoms occupying only one octahedral sublattice. This indicates that the long-existing thermodynamic mean-field theory of ordering of carbon in alpha-Fe assuming strong preference of carbon atoms to occupy only one octahedral sublattice is deficient. It is shown that the presence of carbon atoms only at one octahedral sublattice in the experimentally observed martensitic phase, alpha'-Fe, is a self-trapping effect. It occurs during a displacive martensitic transformation from gamma- to alpha-Fe, which kinematically transfers the carbon atoms from a single fcc octahedral sublattice to one of three octahedral sublattices, where they appear to be locked by a consequent tetragonal distortion minimizing elastic energy of the phase. The latter creates a strong preference for carbon atoms to be only at one already occupied octahedral sublattice preventing them from further distribution over the other sublattices.
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| 43. |
- Ruban, Andrei V.
(författare)
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Single-site mean-field approach to thermal defects in binary ordered alloys
- 2014
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 94:11, s. 1192-1201
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Tidskriftsartikel (refereegranskat)abstract
- A single-site mean-field approach for the concentration of thermal defects in a binary intermetallic AB compound is proposed, which is a modification of previously existing Wagner-Schottky-type models. A numerical investigation of the model is done for the case of thermal defects in NiAl.
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| 44. |
- Ruban, Andrei V., et al.
(författare)
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Spin-wave method for the total energy of paramagnetic state
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 85:17, s. 174407-
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Tidskriftsartikel (refereegranskat)abstract
- Spin-wave formalism provides a convenient alternative way of modeling the high-temperature paramagnetic state for a certain type of magnets within the framework of Hamiltonian-type electronic-structure methods. For Heisenberg systems, it is formally equivalent to the so-called disordered local moment approach, which is usually used in the methods based on the coherent potential approximation within the Green's function or multiple-scattering techniques. In this paper, we demonstrate that the spin-wave method has certain advantages when it comes to the calculation of forces and relaxations. It also allows one to take magnetic short-range-order effects into consideration. As examples of the application of the spin-wave method, we calculate the energy of the paramagnetic state in fcc Co and bcc Fe, the vacancy formation energy, elastic constants, and phonon spectrum in bcc paramagnetic Fe. We demonstrate that magnetic short-range-order effects play a crucial role in the mechanical stabilization of the bcc Fe at high temperature in the paramagnetic state.
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| 45. |
- Sax, C. R., et al.
(författare)
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Interactions and phase transformations in Fe-Pd
- 2014
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 89:1, s. 014201-
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Tidskriftsartikel (refereegranskat)abstract
- Interactions in Fe-Pd were studied using diffuse x-ray scattering and first-principles calculations. Diffuse x-ray scattering was performed from single crystals of Fe-38.2 at. % Pd and Fe-81.0 at. % Pd to investigate states of thermal equilibrium at 1023 K and 1073 K, respectively. Short-range-order scattering was separated and effective pair interaction (EPI) parameters were determined using the inverse Monte Carlo method. The EPI parameters are found to strongly vary with respect to data from a previous investigation of Fe-50 at. % Pd. Electronic-structure calculations of effective cluster interaction (ECI) parameters for these states showed the importance of considering multibody interactions and applying the disordered local moment model of the magnetic state: in the ferromagnetic model, the strength of the interactions gets overestimated. Close agreement is reached for short-range order between calculations and the present scattering experiments. Using either a linear compositional variation of the EPI parameters or ECI parameters for alloys with other Pd fractions, the shape of the order-disorder transition line on the Pd-rich side could be reproduced.
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| 46. |
- Schnöfeld, B., et al.
(författare)
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Order and disorder in Ni-Pt single crystals
- 2011
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Konferensbidrag (refereegranskat)abstract
- Single crystals of Ni-25.6 at.% Pt and Ni-87.8 at.% Pt were investigated by diffuse x-ray scattering for states of thermal equilibrium (923 K and 603 K, respectively). The separated short-range order scattering showed local maxima at 100 positions. Effective pair interaction parameters, as determined by the inverse Monte Carlo method, show a strong composition dependence of the nearest-neighbor interaction parameter. First-principles calculations are consistent with this finding and reveal a large contribution due to lattice strain. Based on values of the ordering energy, NiPt3 with L1 2 structure was considered as a plausible new intermetallic phase, with Monte Carlo simulations giving an order-disorder transition temperature of 650 K. A single crystal of Ni-75.2 at.% Pt, quenched from 1073 K and aged at 613 K, showed L12-type ordering, reaching a long-range order parameter of 0.50(4) after 800 h.
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| 47. |
- Schönfeld, B., et al.
(författare)
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Atomic ordering in Au-(42 to 50) at.% Pd : A diffuse scattering and first-principles investigation
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 85:1, s. 014204-
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Tidskriftsartikel (refereegranskat)abstract
- Atomic ordering in Au-Pd alloys was studied by diffuse x-ray scattering and first-principles methods. Diffuse scattering was done of a single crystal of Au-48 at.% Pd that was aged at 703 K for 24 days. The weakly modulated short-range-order scattering exhibits diffuse maxima with an incommensurate wave vector, which can be related to a Fermi-surface nesting mechanism. From effective pair interaction parameters determined by the inverse Monte Carlo method, a one-dimensional long-period superstructure of the CH structure, LPS1, was found for AuPd. Concurrent electronic-structure calculations of the effective cluster interaction (ECI) parameters indicated the presence of another closely related superstructure, LPS2, at 0 K. At the same time, direct first-principles calculations of the total energies of the CH structure and further one-dimensional long-period superstructures predicted the stabilization of LPS4. Although the energy differences between these structures are small and a complex behavior of the effective interactions is expected due to the Fermi-surface nesting, experimental data and theoretical results both support the stabilization of a long-period superstructure of the CH structure for AuPd at 0 K. The ECI parameters determined by the screened generalized perturbation method also predicted a ground-state structure different from Au(7)Pd(5), previously obtained from cluster expansion calculations. Its energetic preference was confirmed by direct total-energy calculations.
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| 48. |
- Singh, Prashant, et al.
(författare)
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Magnetic behaviour of AuFe and NiMo alloys
- 2011
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Ingår i: Pramana (Bangalore). - : Springer Science and Business Media LLC. - 0304-4289 .- 0973-7111. ; 76:4, s. 639-656
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Tidskriftsartikel (refereegranskat)abstract
- We study the electronic structure and a mean-field phase analysis based on the pair-pair energies derived from first-principles electronic structure calculations of AuFe and NiMo alloys. We have used the tight-binding linear muffin-tin orbitals-based augmented space recursion (TB-LMTO-ASR) method to do so. We investigate different behaviours of the two alloy systems by mapping the problems onto equivalent Ising models and then discuss the magnetic phase diagrams using the calculated pair energies. All three phases: paramagnetic, random ferromagnetic and spin glass, have been studied.
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| 49. |
- Yeddu, Hemantha Kumar, et al.
(författare)
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Multi-length scale modeling of martensitic transformations in stainless steels
- 2012
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 60:19, s. 6508-6517
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Tidskriftsartikel (refereegranskat)abstract
- In the present work a multi-length scale model is developed to study both the athermal and stress-assisted martensitic transformations in a single crystal of 301 type stainless steel. The microstructure evolution is simulated using elastoplastic phase-field simulations in three dimensions. The input data for the simulations is acquired from a combination of computational techniques and experimental works. The driving force for the transformation is calculated by using the CALPHAD technique and the elastic constants of the body-centered cubic phase are calculated by using ab initio method. The other input data is acquired from experimental works. The simulated microstructures resemble a lath-type martensitic microstructure, which is in good agreement with the experimental results obtained for a stainless steel of similar composition. The martensite habit plane predicted by the model is in accordance with experimental results. The Magee effect, i.e. formation of favorable martensite variants depending on the loading conditions, is observed in the simulations. The results also indicate that anisotropic loading conditions give rise to a significant anisotropy in the martensitic microstructure.
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