S 91 Suetin, D. V. Structural, elastic and electronic properties and formation energiesfor hexagonal (W0.5Al0.5)C in comparison with binary carbidesWC and Al4C3 from first-principles calculations / D. V. Suetin, I. R. Shein, A. L. Ivanovskii // Physica B. - 2008. - Vol. 403. - P. 2654-2661 : il. - Bibliogr. : p. 2660-2661 (41 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): РАСЧЕТЫ ПЕРВОПРИНЦИПНЫЕ -- КАРБИДЫ -- W-Al-C -- СВОЙСТВА УПРУГИЕ -- СВОЙСТВА СТРУКТУРНЫЕ -- СВОЙСТВА ЭЛЕКТРОННЫЕ Аннотация: First principle calculations have been performed with the purpose to understand the peculiarities of the structural, elastic parameters and electronic properties and interatomic bonding for novel hexagonal carbide (W0.5Al0.5)C in comparison with binary phases WC and Al4C3. The geometries of all phases were optimized and their structural, elastic parameters and theoretical density were established. Besides, we have evaluated the formation energies (Eform) of W0.5Al0.5C for different possible preparation routes (namely for the reactions with the participation of simple substances (metallic W, Al and graphite, binary W or Al carbides and metallic Al and W, or binary W and Al carbides). The results show that the synthesis of the ternary carbide from simple substances is more favorable in comparison with the reactions with participation of W and Al carbides. Moreover, band structures, total and partial densities of states were obtained and analyzed systematically for (W0.5Al0.5)C, WC and Al4C3 phases in comparison with available theoretical and experimental data. The bonding picture in W0.5Al0.5C was described as a mixture of metallic, ionic and covalent contributions with the high anisotropy for the covalent W–C and Al–C bonds, where p–p like Al–C bonds become weaker than p–d like W–C bonds Полный текст |