| 1. |
- Artemiev, AN, et al.
(författare)
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Focusing of hard synchrotron radiation by a refracting glassy carbon lens
- 2004
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Ingår i: Crystallography Reports. - 1063-7745. ; 49, s. 166-169
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Tidskriftsartikel (refereegranskat)abstract
- The first experimental study of focusing synchrotron radiation by a parabolic planar glassy-carbon lens is presented. The lens consists of four biconcave single lenses with a curvature radius of 0.2 mm and a relief height comparable with the lens aperture (similar to1 mm). One lens gives rise to the formation of a linear focus with a length comparable with the height of a parabolic profile. The use of two lenses in the cross geometry provides the formation of a pointlike focus. The experiment was performed with the use of synchrotron radiation from the bending magnet BM-5 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The monochromated synchrotron radiation with an energy of 12.2 keV was focused at a distance of 19 m from the lens. The causes that gave rise to focus broadening in comparison with the focus following from the theory of an ideal lens are discussed.
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| 2. |
- Bak-Misiuk, J., et al.
(författare)
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Variation of strain in granular GaAs:MnAs layers
- 2013
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Ingår i: Crystallography Reports. - 1063-7745. ; 58:7, s. 998-1001
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Tidskriftsartikel (refereegranskat)abstract
- Granular GaAs(MnAs) layers with different Mn concentration and various layer thickness were grown by MBE method and subjected to annealing at 500A degrees C under ambient and enhanced hydrostatic pressure. Distinct influence of hydrostatic pressure applied during annealing on strain state of layers as well as on hexagonal MnAs inclusions was found. Pressure induced strain of inclusions is related to different bulk moduli of GaAs and of hexagonal MnAs. Formation of hexagonal inclusions depends on concentration of Mn in interstitial position in as-grown samples.
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| 3. |
- Grippa, Alexander Yu, et al.
(författare)
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Crystal Structure of BaNb0.9S3
- 2001
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Ingår i: Crystallography Reports. - : American Institute of Physics. - 1063-7745. ; 46:3, s. 373-376
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Tidskriftsartikel (refereegranskat)abstract
- Single crystals of the composition BaNb[sub 0.9]S[sub 3] have been synthesized from the BaS, Nb, and S mixture and the BaCl[sub 2] flux at 900°C. The BaNb[sub 0.9]S[sub 3] structure was refined by X-ray single-crystal and electron diffraction data. The compound is crystallized in the sp. gr P6[sub 3]/mmc (z = 2) with the unit-cell parameters a = 6.839(1) Å and c = 5.745(1) Å. It was established that the cationic vacancies in the niobium positions are statistically distributed over the structure.
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| 4. |
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| 5. |
- Ivanov, SA, et al.
(författare)
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Specific features of the structure and electrical conductivity of the magnetically ordered oxide (La0.9Sr0.1)(Fe0.8Mg0.2)O3-y
- 2008
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Ingår i: Crystallography Reports. - 1562-689X .- 1063-7745. ; 53:1, s. 68-75
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Tidskriftsartikel (refereegranskat)abstract
- The structure of the (La0.9Sr0.1)(Fe0.8Mg0.2)O-3 (-) (y) oxide is investigated using neutron diffraction at temperatures of 10, 295, 500, 700, and 1000 K. The results of the structure refinement are in good agreement with the experimental data on the electrical conductivity and confirm the inference that the oxidation state of iron cations is higher than 3+ and that the structure of the compound is antiferromagnetically ordered at temperatures below 500 K.
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| 6. |
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| 7. |
- Rozhdestvina, V. I, et al.
(författare)
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Single-crystalline cooperite (PtS) : crystal-chemical characterization, ESR spectroscopy, and Pt-195 NMR spectroscopy
- 2008
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Ingår i: Crystallography reports (Print). - 1063-7745 .- 1562-689X. ; 53:3, s. 391-397
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Tidskriftsartikel (refereegranskat)abstract
- Single-crystalline cooperite (PtS) with a nearly stoichiometric composition was characterized in detail by X-ray diffraction, electron-probe X-ray microanalysis, and high-resolution scanning electron microscopy. For the first time it was demonstrated that Pt-195 static and MAS NMR spectroscopy can be used for studying natural platinum minerals. The 195pt chemical-shift tensor of cooperite was found to be consistent with the axial symmetry and is characterized by the following principal values: delta(xx) = -5920 ppm, delta(yy) = -3734 ppm, delta(zz) = +4023 ppm, and delta(iso) = -1850 ppm. According to the ESR data, the samples of cooperite contain copper(II), which is adsorbed on the surface during the layer-by-layer crystal growth and is not involved in the crystal lattice.
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| 8. |
- Serovaiskii, A. Y., et al.
(författare)
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Investigation of the LiCu2O2 Phase Samples Treated under High Thermobaric Conditions
- 2021
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Ingår i: Crystallography reports (Print). - : Pleiades Publishing Ltd. - 1063-7745 .- 1562-689X. ; 66:6, s. 1060-1065
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Tidskriftsartikel (refereegranskat)abstract
- Orthorhombic lithium cuprate LiCu2O2 was exposed to high temperature and pressure of 950 degrees C and 4.5 GPa. X-ray diffraction studies indicate that the treated samples of LiCu2O2 had tetragonal symmetry, in contrast to the orthorhombic one of the phase synthesized at atmospheric pressure. Temperature dependences of dielectric permittivity epsilon and tangent of dielectric loss tan delta, as well as DC (direct current), resistivity, rho were investigated in the temperature range 77-296 K. No anomalous changes of the studied parameters inherent in the phase transitions were detected in this temperature range. The rho(T) dependences were common to semiconductors. These dependences were linearized in the Mott coordinates log rho-1/T (0.25). It indicated the variable length hopping mechanism of conduction between the next nearest neighbors in the studied samples.
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| 9. |
- Stepantsov, E.A., et al.
(författare)
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Investigation into the growth and structure of thin-film solid solutions of iron-based superconductors in the FeSe0.92-FeSe0.5Te0.5 system
- 2013
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Ingår i: Crystallography reports (Print). - 1063-7745 .- 1562-689X. ; 58:5, s. 735-738
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of FeSe0.92 and FeSe0.5Te0.5 iron chalcogenide superconductors and solid solutions containing these components in different ratios have been grown on the surface of LaAlO3 (10 1¯ 2) crystals by pulsed laser deposition. Films of solid solutions have been deposited by simultaneous laser ablation from two targets of the FeSe0.92 and FeSe0.5Te0.5 stoichiometric compositions onto one substrate. An X-ray diffraction study of the film structure shows that the films grown are epitaxial and their lattice parameters regularly vary with the ratio of the deposited components, which was controllably varied by changing the ablation intensities from the targets.
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| 10. |
- Stepantsov, Evgeny, et al.
(författare)
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Ablation replacement of iron with Co, Mn, Ni, and Cu during growth of iron-based superconductor films in the Fe0.9M0.1Se0.92 system
- 2014
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Ingår i: Crystallography reports (Print). - 1063-7745 .- 1562-689X. ; 59:5, s. 739-743
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of ironbased chalcogenide superconductors FeSe0.92, with iron partially replaced (atleast up to 10 at %) by elements such as cobalt, nickel, manganese, or copper, have been grown on the surfaceof (10 2) LaAlO3 crystals. Growth is performed by the laser ablation of a target prepared in the form of aceramic pellet by hightemperature synthesis and the sintering of preliminarily pressed stoichiometric mixture of powders. Iron in these ceramics is replaced with an alloying metal by no more than 3 at %. The rest(7 at %) of the metal is in the form of precipitates of other phases. Xray diffraction analysis of the grown filmshas shown that they are singlecrystal and free of any precipitates of other crystallographic orientations andphases. This is evidence of the complete (10 at %) replacement of iron with a doping metal in the film structure. This circumstance indicates that the synthesis of components occurs more actively and completely during laser ablation (than in solidphase chemical reactions) as a result of the transformation of multicomponent target material into plasma. Thus, one can fabricate film materials in a wider range of chemical compositions than in the form of solidphase synthesized ceramics.
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