Crystal Growth and Structure and Magnetic Properties of the 5d Oxide Ca3LiOsO6: Extended Superexchange Magnetic Interaction in Oxide

Abstract

Crystals of the newly synthesized compound Ca₃LiOsO₆ were grown by a flux method using LiCl and KCl, followed by single-crystal X-ray diffraction (XRD), low-temperature powder XRD, and measurements of ac and dc magnetic susceptibility and specific heat. The data indicate that Ca₃LiOsO₆ has a fully opened electronic gap with an antiferromagnetic ordered state, consistent with suggestions from the first-principles study. The observed magnetic transition temperature is 117 K, too high to be caused only by a direct spin−spin interaction. It appears that the original superexchange magnetic path Os−O−Os is absent; thus, the extended superexchange path (Os−O)−(O−Os) can be expected to be responsible for the 117 K magnetic order. If this is true, Ca₃LiOsO₆ would be highly valuable to study the nature of extended superexchange magnetic interactions in solids.