| 1. |
- Dubrovinsky, L., et al.
(författare)
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Noblest of all metals is structurally unstable at high pressure
- 2007
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 98:4
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Tidskriftsartikel (refereegranskat)abstract
- In a series of experiments in externally electrically heated diamond anvil cells we demonstrate that at pressures above similar to 240 GPa gold adopts a hexagonal-close-packed structure. Ab initio calculations predict that at pressures about 250 GPa different stacking sequences of close-packed atomic layers in gold become virtually degenerate in energy, strongly supporting the experimental observations.
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| 2. |
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| 3. |
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| 4. |
- Isaeva, E. I., et al.
(författare)
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Ab initio phonon calculations for Ll(2) Ni3Al and B2NiAl
- 2004
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Ingår i: Solid State Communications. - : Elsevier BV. - 0038-1098 .- 1879-2766. ; 129:12, s. 809-814
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Tidskriftsartikel (refereegranskat)abstract
- The phonon spectra and phonon density of states of the Ni3Al and NiAl intermetallic compounds are calculated from first principles using the linear response method in conjunction with ultrasoft pseudopotentials. The calculated phonon dispersion curves are in good agreement with available experimental results from inelastic neutron scattering.
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| 5. |
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| 6. |
- Simak, Sergey, 1967-, et al.
(författare)
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The role of orthorhombic distortions in gallium under high hydrostatic pressure
- 2006
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Ingår i: Journal of Physics and Chemistry of Solids. - : Elsevier BV. - 0022-3697 .- 1879-2553. ; 67:10-sep, s. 2132-2135
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Tidskriftsartikel (refereegranskat)abstract
- We have performed a detailed analysis ofthedouble-well feature ofthetotal energy fortheGa-III phase as a function of tetragonal andorthorhombicdistortionsoftheface-centered cubic (fcc) lattice. We demonstrate that inthelow-pressureregion this double-well feature disappears and only one minimum exists. In order to reveal this result,thepossibility oforthorhombicdistortionshas to be taken into account. At elevatedpressurebetween 58 and 84 GPa,thesecond minimum becomes pronounced, but never develops into a separate local minimum up tothetransformation intothefcc phase.
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| 7. |
- Skorodumova, Natalia V., et al.
(författare)
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Random conductivity of delta-Bi2O3 films
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 86:24
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Belonoshko, Anatoly B., et al.
(författare)
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High-pressure melting of molybdenum
- 2004
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 92:19
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Tidskriftsartikel (refereegranskat)abstract
- The melting curve of the body-centered cubic (bcc) phase of Mo has been determined for a wide pressure range using both direct ab initio molecular dynamics simulations of melting as well as a phenomenological theory of melting. These two methods show very good agreement. The simulations are based on density functional theory within the generalized gradient approximation. Our calculated equation of state of bcc Mo is in excellent agreement with experimental data. However, our melting curve is substantially higher than the one determined in diamond anvil cell experiments up to a pressure of 100 GPa. An explanation is suggested for this discrepancy.
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| 9. |
- Colarieti-Tosti, Massimiliano, et al.
(författare)
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First-principles theory of intermediate-valence f-electron systems
- 2004
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 93:9, s. 096403-
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Tidskriftsartikel (refereegranskat)abstract
- We propose a first-principles based method for calculating the electronic structure and total energy of solids in an intermediate-valence configuration. The method takes into account correlation effects (d-f Coulomb interaction) and many-body renormalization of the effective hybridization parameter of the f system. As an example, the formation of a pressure-induced intermediate-valence state in Yb is considered and its electronic structure and equation of state are calculated and compared to experimental data. The agreement is found to be excellent for both properties, and we argue that the developed method, which applies to any element or compound, provides for the first time a quantitative theoretical treatment of intermediate-valence materials.
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| 10. |
- Haussermann, U., et al.
(författare)
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Metal-nonmetal transition in the boron group elements
- 2003
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 90:6
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Tidskriftsartikel (refereegranskat)abstract
- Structural competition in boron group elements has been studied by means of ab initio calculations. For boron we predict a structural change alpha-B-->alpha-Ga accompanied by a nonmetal-metal transition at a pressure of about 74 GPa. For Al and Ga we find an icosahedron based elemental modification (alpha-B) 0.22 and 0.05 eV/atom, respectively, higher in energy than the corresponding metallic ground state structures. In particular, the low energy difference for Ga raises expectations into the experimental feasibility of new modifications for these elements, especially in nanosized systems.
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