Magnetically Frustrated Double Perovskites: Synthesis, Structural Properties, and Magnetic Order of Sr₂<i>B</i>OsO₆ (<i>B</i> = Y, In, Sc)

Abstract

Abstract Double perovskites Sr 2 B OsO 6 ( B = Y, In, and Sc) were prepared from the respective binary metal oxides, and their structural, magnetic, and electronic properties were investigated. At room temperature all these compounds crystallize in the monoclinic space group P 2 1 / n . They contain magnetic osmium (Os 5+ , t 2g 3 ) ions and are antiferromagnetic insulators with Néel temperatures T N = 53 K, 26 K, and 92 K for B = Y, In, and Sc, respectively. Powder neutron diffraction studies on Sr 2 YOsO 6 and Sr 2 InOsO 6 showed that the crystal structures remain unchanged down to 3 K. The Y and In compounds feature a type I antiferromagnetic spin structure with ordered Os moments of 1.91 μ B and 1.77 μ B , respectively. The trend in T N does not simply follow the development of the lattice parameters, which suggests that d 0 compared to d 10 ions on the B site favor a somewhat different balance of exchange interactions in the frustrated Os 5+ fcc ‐like lattice.