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Using band-structure calculations within the FLAPW (Full-Potential Linearized Augmented-Plane-Wave) model, information is obtained regarding the energy, charge and spatial characteristics of aluminium nitride and its solid solutions with oxygen and aluminium. As established, the formation of these solutions is accompanied by a reduction in electron density in their interatomic regions. The accompanying decrease in the covalence of interatomic interactions leads to both a reduction in binding energies and an increase in the volumes of elementary cells within the compounds. The transition from aluminium nitride to its energetically 'nearest' oxide is accompanied by a decrease in binding energy by 1.25 eV, which corresponds to over 14.5·103 K on the temperature scale. This correlation underscores the high resistance of aluminium nitride to oxidation processes. The formation of an alloy with aluminium incorporation becomes even less likely due to the larger decrease in binding energy by 2.84 eV. [ABSTRACT FROM AUTHOR]

Information on the energy, charge, and spin characteristics of Pd1-xMexMnSn alloys (Me = Co, Ni, x = 0.0--1.0) is obtained using band calculations within the FLAPW (full-potential linearized augmented-plane-wave) model. As determined, an increase in the concentration of the cobalt or nickel atoms leads to an increase in the interatomic electron density inside the alloys. This results in both a concurrent reduction in the parameters of their crystal lattices and an increase in the binding energies of the atoms. The number of electrons Q within the atomic spheres of Pd, Mn, and Sn in cobalt-containing alloys exceeds the corresponding values for nickel-containing phases, and the dependences of Q exhibit a systematic tendency to increase with the growth of substitutional- atoms' concentrations. The observed polarization of valence electrons leads to the appearance of magnetic moments on the atoms of the alloys. The magnetic moments of metal atoms are ferromagnetically ordered, and their magnitude depends on the type and concentration of substitutional atoms. [ABSTRACT FROM AUTHOR]

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Using zone calculations in the FLAPS (the full-potential linearized augment- ed-plane-waves) model, information is obtained on the energy, charge and spin characteristics of Pt1-xMexMnSb alloys (Me = Ni, Au, x = 0.0--1.0). As established, with an increase in the concentration of nickel or gold atoms the interatomic spatial density of electrons decreases, covalent bonds weaken and the binding energies of atoms in alloys decrease. As found, the dominant con- tributions to the formation of magnetic moments are made by 3d electrons of manganese atoms, and the polarization of electrons at Fermi levels depends on the composition of alloys. [ABSTRACT FROM AUTHOR]

Using zone calculations in the FLAPW (the full-potential linearized augmented- plane-waves) model, information on the energy, charge and spin characteristics of Pt1−xNixMnSb alloys (x = 0.0–1.0) is obtained. As established, with an increase in the concentration of nickel atoms in Pt1−xNixMnSb alloys, the interatomic space density of electrons decreases, covalent bonds weaken, and the cohesive energies of the alloys decrease. The dominant contributions to the formation of magnetic moments in Pt1−xNixMnSb alloys are provided by 3d electrons of manganese atoms. In alloys with х ≥ 0.50, a complete polarization of Fermi electrons is registered that converts these alloys to a half-metallic state. [ABSTRACT FROM AUTHOR]

The transformations of platinum(II) and platinum(IV) complexes with inner- and outer-sphere ligands by the action of (+)-α-pinene and (+)-limonene were studied. Reduction of the metal complex is the main process whose rate increases in the following outer-sphere ligand series: (Me2SO)2H+ < Et3 NH+ < K+ < < H+. The reaction of K2PtCl4 with α-pinene gave cis-terpine monohydrate and dichloro-η4-[ p-mentha- 1,8(9)-diene]platinum(II), and their structure was proved by X-ray analysis. The complex belongs to monoclinic crystal system, the Pt-Cl and Pt-C bonds therein have different lengths, the ClPtCl angle is 85.88°, and the C=C bond plane is orthogonal to the square coordination core. Dichloro-η4-[ p-mentha-1,8(9)-diene]- platinum(II) was tested as catalyst in the hydrosilylation of acetophenone with diphenylsilane. [ABSTRACT FROM AUTHOR]