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Abstract: X-ray absorption near-edge spectroscopy (XANES) spectra of Mn1−x Cr x Au2 (x =0, 0.05, 0.08, and 0.13) are presented and compared with theoretical XANES spectra and site- and momentum-decomposed partial density of states. Extended X-ray absorption fine structure spectra of these compounds are also analyzed to yield the bonding parameters. [Copyright &y& Elsevier]

Abstract: X-ray absorption near-edge spectroscopy (XANES) spectra at the Ni K-, In L3-, and In K-edge of Ni3In and Ni13In9 are presented and compared with theoretical XANES spectra and site- and momentum-decomposed partial density of states derived from first-principles calculation. The agreement between theory and experiment is better for Ni3In than for Ni13In9. Extended X-ray absorption fine structure spectra of Ni3Al, Ni3Ga, Ni3In, and Ni13In9 are also analyzed to yield the bonding parameters. [Copyright &y& Elsevier]

The dielectric functions and optical conductivities of polycrystalline Ni3Al, Ni3Ga, and Ni3In from 0.6 to 4 eV were measured by spectroscopic ellipsometry. The experimental results are compared with the theoretical curves. The agreement between theory and experiment is best for Ni3Al, less for Ni3Ga, and least for Ni3In. [Copyright &y& Elsevier]

Calculations with full structural optimization were conducted by generalized gradient approximation (GGA) with correlation effect correction (GGA + U) based on density functional theory. The stable structures, magnetic stable phases, and electronic structures of the double perovskites of Sr2BB'O6 (B = Co, Cu, and Ni; B' = Mo, W, Tc, and Re; and BB' = FeTc) were investigated. All compounds, except for Sr2NiMoO6 and Sr2NiWO6, can be half-metallic (HM) materials in the GGA scheme; Sr2NiMoO6 and Sr2NiWO6 are ferromagnetic (FM) insulators. Sr2FeTcO6, Sr2CoWO6, and Sr2NiTcO6 are stable ferrimagnetic (FiM)-HM compounds in the GGA and GGA + U schemes. Given the small energy difference between their antiferromagnetic and FiM states, Sr2CoTcO6, Sr2CuMoO6, Sr2NiMoO6, Sr2NiWO6, and Sr2NiReO6 can coexist. The mechanisms of the HM-FiM properties can be described by d-d' hybridization with double-exchange interaction. [ABSTRACT FROM AUTHOR]