S 53 Shein, I. R. Structural, elastic and electronic properties of superconducting anti-perovskites MgCNi3, ZnCNi3 and CdCNi3 from first principles [Text] / I. R. Shein, V. V. Bannikov, A. L. Ivanovskii // Physica C: Superconductivity and Its Applications (Amsterdam, Netherlands). - 2008. - Vol. 468, № 1. - P1-6. - Bibliogr. : p. 6 (29 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): СВЕРХПРОВОДЯЩИЕ АНТИПЕРОВСКИТЫ -- УПРУГОСТЬ Аннотация: First principle total energy calculations using the full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) for the exchange-correlation potential were performed to investigate the systematic trends for structural, elastic and electronic properties of the family of superconducting anti-perovskites MCNi3 depending from the type of M cations (M are Mg, Zn and Cd). In result the optimized lattice parameters, independent elastic constants (C11, C12 and C44), bulk modulus B, compressibility b, shear modulus G and tetragonal shear modulus G0 are evaluated. Further, for the first time the numerical estimates of a set of elastic parameters (bulk and shear modulus, Young’s modulus Y, Poisson’s ratio (m), Lame´’s coefficients (l, k)) of the polycrystalline superconducting MCNi3 ceramics (in framework of the Voigt–Reuss–Hill approximation) were performed. Besides, the band structures, densities of states (DOS), total and site-projected l-decomposed DOS at the Fermi level, the shapes of the Fermi surfaces, the Sommerfeld’s coefficients and the molar Pauli paramagnetic susceptibility for these anti-perovskites were obtained and analyzed in comparison with the available theoretical and experimental data Полный текст |
B 22 Bannikov, V. V. Band structure, elastic and magnetic properties, and stability of antiperovskites MCNi3 (M = Y-Ag) according to FLAPW-GGA calculations [Текст] / V. V. Bannikov, I. R. Shein, A. L. Ivanovski // Physics of the Solid State. - 2007. - Vol. 49, № 9. - С. 1704-1714. - Библиогр. : с. 1713 (41 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): АНТИПЕРОВСКИТЫ -- КАРБИДЫ -- МЕЖАТОМНОЕ ВЗАИМОДЕЙСТВИЕ Аннотация: Using the full-potential linearized augmented plane wave method (FLAPW) and the WIEN2k software package, calculations of the band structure and the elastic and magnetic properties of the ternary antiperovskite carbides MCNi3, where M = Y, Zr,..., Ag (overall, nine compounds) are performed and the features of interatomic interactions in them are considered. Stability of these antiperovskite compounds depending on the 4d metal is discussed based on the calculated energies of formation of MCNi3 from the corresponding elements (according to the formal reaction M + C + 3Ni - MCNi3), and the conclusion is drawn that the YCNi3, ZrCNi3, and PdCNi3 antiperovskites can be synthesized. The obtained results are compared with the available data on known isostructural nickel-based carbides (antiperovskites MgCNi3, ZnCNi3) Полный текст |
B 22 Bannikov, V. V. Novel magnetic half-metallic materials based on ionic insulators doped with nonmagnetic impurities: MgO + B, C, N Systems [Текст] / V. V. Bannikov, I. R. Shein, A. L. Ivanovskii // Technical Physics Letters. - 2007. - Vol. 33, № 7. - С. 541-544. - Библиогр. : с. 544 (15 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: It is established that magnesium oxide (a nonmagnetic ionic insulator) exhibits a transition to the state of a magnetic half-metal upon the introduction of nonmagnetic impurities (boron, carbon, or nitrogen) into the crystal lattice. The possibility of obtaining novel magnetic materials for spintronics by doping ionic insulators with nonmagnetic impurities is discussed. Полный текст |
B 22 Bannikov, V. V. Electronic structure, chemical bonding and elastic properties of the first thorium-containing nitride perovskite TaThN3 [Текст] / V. V. Bannikov, I. R. Shein, A. L. Ivanovskii // Physica Status Solidi RRL: Rapid Research Letters. - 2007. - Vol. 1, № 3. - С. 89-91. - Библиогр. : с. 91 (15 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The full-potential linearized augmented plane wave method with the generalized gradient approximation for the exchanged and correlation potential (LAPW-GGA) is used to understan the electronic and elastic properties of the first thoriumcontaining nitride perovskite TaThN3. Total and partial density of states, charge distributions as well as the elastic constants, bulk modulus, compressibility, shear modulus, Young modulus and Poisson ratio are obtained for the first time an analyzed in comparison with cubic ThN. The chemical bonding in TaThN3 is a combination of ionic Th–N and of mixed covalent–ionic Ta–N bonds. The cubic TaThN3 is semiconducting with the direct gap at about 0.65 eV. Полный текст |
B 22 Bannikov, V. V. Electromagnetic water treatment. Part 1 [Текст] / V. V. Bannikov // Vodosnabzhenie i Sanitarnaya Tekhnika. - 2005. - № 5. - С. 17-20 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
M 17 Magnetism without magnetic ions in non-magnetic perovskites SrTiO3, SrZrO3 and SrSnO3 [Text] / V. V. Bannikov, I. R. Shein, V. L. Kozhevnikov, A. L. Ivanovskii // Journal of Magnetism and Magnetic Materials. - 2008. - Vol. 320, № 6. - P936-942. - Bibliogr. : p. 941-942 (46 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ПЕРОВСКИТЫ -- МАГНЕТИЗМ -- ПЕРВОПРИНЦИПНЫЕ РАСЧЕТЫ Аннотация: Using the full-potential linearized augmented plane-wave (FP-LAPW) method with the generalized gradient approximation (GGA) for the exchange-correlation potential, we studied spin polarization induced by replacement of oxygen atoms by non-magnetic 2p impurities (B, C and N) in non-magnetic cubic SrMO3 perovskites, where M ¼ Ti, Zr and Sn. The results show that the magnetization may appear because of the spin–split impurity bands inside the energy gap of the insulating SrMO3 matrix. Large magnetic moments are found for the impurity centers. Smaller magnetic moments are induced on the oxygen atoms around impurities. It is shown that SrTiO3:C and SrSnO3:C should be magnetic semiconductors while other compounds in this series (SrTiO3:B, SrTiO3:N and SrZrO3:C) are expected to exhibit magnetic half-metallic or pseudo-half-metallic properties Полный текст |
S 53 Shein, I. R. Structural, elastic and electronic properties of superconducting anti-perovskites MgCNi3, ZnCNi3 and CdCNi3 from first principles [Текст] / I. R. Shein, V. V. Bannikov, A. L. Ivanovskii // Physica C: Superconductivity and Its Applications (Amsterdam, Netherlands). - 2008. - Vol. 468, № 1. - С. 1-6 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
B 22 Bannikov, V. V. Novel magnetic half-metallic materials based on ionic insulators doped with nonmagnetic impurities: MgO + B, C, N Systems [Текст] / V. V. Bannikov, I. R. Shein, A. L. Ivanovskii // Technical Physics Letters. - 2007. - Vol. 33, № 7. - С. 541-544. - Библиогр. : с. (12 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ |
E 43 Electronic structure and magnetic properties of double perovskites Sr2FeMO6 (M = Sc, Ti, ..., Ni, Cu) according to the data of FLAPW-GGA band structure calculations / V. V. Bannikov, I. R. Shein, V. L. Kozhevnikov, A. L. Ivanovskii // Journal of Structural Chemistry. - 2008. - Vol. 49, № 5. - P781-787 : il. - Bibliogr. : p. 786-787 (23 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): Sr2FeMO6 -- ДВОЙНЫЕ ПЕРОВСКИТЫ -- МАГНЕТИЗМ -- МОДЕЛИРОВАНИЕ Аннотация: Changes in the electronic structure and magnetic characteristics of Sr2FeMO6 double perovskites were studied by the FLAPW-GGA ab initio band structure method in relation to the type of the cation M = Sc, Ti, ..., Ni, Cu Полный текст |
B 22 Bannikov, V. V. Structural, electronic, and magnetic properties of CaCNi3, SrCNi3, and BaCNi3 antiperovskites in comparison to superconducting MgCNi3 / V. V. Bannikov, I. R. Shein, A. L. Ivanovskii // Journal of Structural Chemistry. - 2010. - Vol. 51, № 1. - P170-172 : il. - Bibliogr. : p. 172 (10 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): АНТИПЕРОВСКИТЫ -- МАГНЕТИЗМ -- МОДЕЛИРОВАНИЕ Аннотация: Within the first principle FLAPW-GGA band method we predict the structural, electronic, and magnetic properties of CaCNi3, SrCNi3, and BaCNi3 hypothetical antiperovskites. The results are discussed in comparison to the MgCNi3 isostructural superconductor Полный текст |
B 22 Bannikov, V. V. Isotropic and Anisotropic Exchange Interactions in the Orbitally Degenerate Excited (4A2x2T2) State of a Cr3+ Ion Pair Possessing D3h Symmetry / V. V. Bannikov, B. V. Mitrofanov // Physics of the Solid State. - 2002. - Vol. 44, № 8. - P1550-1552 : il. - Bibliogr. : p. 1552 (4 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ИОНЫ ХРОМА -- ХРОМ -- АНИЗОТРОПИЯ Аннотация: Experimentally observed optical absorption spectra of isolated pairs of chromium ions in Cs3Cr2Br9 corresponding to transitions of pairs from the ground (4A2x 2A2) state to a singly excited (4A2 xT2) state are theoretically interpreted. It is shown that the position of the exchange multiplets in the excited (4A2 x2T2) state is determined mainly by the resonance exchange interactions removing the degeneracy with respect to the exchange by an excitation within the pair. It is established that the observed fine structure of the pair in the (4A2 x2T2) state is due to a superposition of the contributions from the one- and two-center spin–orbit interaction and resonance antisymmetric exchange Полный текст |
B 22 Bannikov, V. V. Double Exchange in Cubic Crystals with Pairs of Exchange-Coupled Mixed-Valence 3d3 –3d4 Ions / V. V. Bannikov, V. Ya. Mitrofanov // Physics of the Solid State. - 2005. - Vol. 47, № 8. - P1532-1534 : il. - Bibliogr. : p. 1534 (6 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): НЕСТЕХИОМЕТРИЯ -- 3-D ИОНЫ -- KZnF3 Аннотация: Specifics of the exchange interaction in mixed-valence Cr2+–Cr3+ 3d-ion pairs in KZnF3 crystals are studied. It is shown that the double-exchange interaction can be significantly reduced by the low-symmetry crystal field created by a compensator. The features of the exchange interaction and optical absorption spectra are qualitatively analyzed Полный текст |
M 17 Magnetic Properties and Electronic Structure of the LaGaO3 Perovskite Doped with Nickel / N. V. Chezhina, E. V. Bodritskaya, N. A. Zhuk, V. V. Bannikov, I. R. Shein, A. L. Ivanovskii // Physics of the Solid State. - 2008. - Vol. 50, № 11. - P2121-2126 : il. - Bibliogr. : p. 2126 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ТВЕРДЫЕ РАСТВОРЫ -- ПЕРОВСКИТЫ -- ДОПИРОВАНИЕ -- НИКЕЛЬ -- ГАЛЛАТ ЛАНТАНА Аннотация: Solid solutions of the composition LaGa1 –xNixO3(0.01<=x<=0.10) are synthesized, and their magnetic and electrical properties are investigated. It is established that the ground state of the Ni(III) atoms is the low-spin state 2Eg; however, in the temperature range under investigation, there occurs the2Eg ->4T1g spin equilibrium. An increase in the nickel concentration leads to an increase in the electron conduction of the solid solutions. The band structure of the LaGa0.5Ni0.5O3 model compound is calculated using the ab initio fullpotential linearized augmented-plane-wave method within the generalized gradient approximation (FLAPWGGA).It is shown that the dominant role in the variations observed in the magnetic and electrical properties of the nonmagnetic semiconductor LaGaO3 upon doping with nickel is played by the Ni 3d(eg ) states Полный текст |