摘要
A new oxide NaCu 3 Fe 2 Os 2 O 12 is synthesized using high pressure and temperature conditions. The Rietveld structural analysis shows that the compound possesses both A- and B-site ordered quadruple perovskite structure in Pn3 symmetry. The valence states of transition metals are confirmed to be Cu 2+ /Fe 3+ /Os 5.5+ . The three transition metals all take part in magnetic interactions and generate strong Cu 2+ (→)Fe 3+ (→)Os 5.5+ (↔) ferrimagnetic superexchange interactions with a high Curie temperature about 380 K. Electrical transport measurements suggest its half-metallic properties. The first-principles theoretical calculations demonstrate that the compound has a spin-down conducting band and a spin-up insulating band with a wide energy gap.