The electrical resistivity and the Hall effect of topological insulator BiTe and BiSe single crystals were studied in the temperature range from 4.2 to 300 K and in magnetic fields up to 10 T. Theoretical calculations of the electronic structure of these compounds were carried out in density functional approach, taking into account spin-orbit coupling and crystal structure data for temperatures of 5, 50 and 300 K.
View Article and Find Full Text PDFCalcium aluminate Ca12Al14O33 initially known as cement compound after a series of structural refinements presented a complex cubic structure. It demonstrates a surprising feature consisting of the occurrence of spherical cavities named as cages. After this, mayenite is regarded as a kind of anti-zeolite.
View Article and Find Full Text PDFOxygen surface exchange and diffusion in CaAlO single crystal were studied by a unique in situ method based on isotope equilibration in the gas phase. Although the interphase exchange rate and oxygen diffusion coefficient demonstrate good agreement with available data, only the employed method is efficient to isolate the contributions of various types of exchange; thus, for the first time, it is possible to estimate the surface heterogeneity of mayenite. The obtained results disprove conclusions previously developed in the literature; the temperature region of 750 °C to 850 °C is not the intermediate region where two types of oxygen diffusion coexist.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
November 2015
In the title compound, C21H22ClNO3, the penta-diene unit is nearly planar [maximum deviation = 0.023 (1) Å], but the carbonyl O atom deviates significantly [by 0.304 (1) Å] from its mean plane, which is twisted with respect to the phenyl and chloro-benzene rings by 71.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
November 2015
In the title compound, C24H18N4O4, the plane of the phenyl ring is inclined to those of the toluene ring and the di-nitro-substituted benzene ring by 66.96 (19) and 47.06 (18)°, respectively, while the planes of the two benzene rings are inclined to one another by 36.
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