Long range magnetic order in spin-orbit coupled double perovskites Ba 2 YRuO 6 and Ba 2 CaOsO 6 probed with neutron scattering and muon spin relaxation

Frustration manifests in the double perovskite lattice A2BB'O6 (Fig. 1), in which the antiferromagnetically correlated B' ions comprise a network of edge-sharing tetrahedra. Perovskites may be synthesized with most elements from the periodic table, enabling systematic studies of frustration as a function of structural distortion, lattice parameter, ionic size, moment size, and spin-orbit coupling (SOC), for example. The latter, in particular, has been explored by Chen et al. [1,2], who found that sizable SOC in d1 and d2 systems yields rich phase diagrams with diverse ground states.