Magnetic order and electronic structure of the 5d3 double perovskite Sr₂ScOsO₆

The magnetic susceptibility, crystal and magnetic structures, and electronic structure of the double perovskite Sr2ScOsO6 are reported. Using both neutron and x-ray powder diffraction we find that the crystal structure is monoclinic P21/n from 3.5 to 300 K. Magnetization measurements indicate an antiferromagnetic transition at TN=92K, one of the highest transition temperatures of any double perovskite hosting only one magnetic ion. Type I antiferromagnetic order is determined by neutron powder diffraction, with an Os moment of only 1.6(1)μB, close to half the spin-only value for a crystal field split 5d electron state with a t2g3 ground state. Density functional calculations show that this reduction is largely the result of strong Os-O hybridization, with spin-orbit coupling responsible for only a ∼0.1μB reduction in the moment.