Investigation of frustrated magnetism in double perovskites

Abstract

This investigation studies the structural and magnetic properties of the double perovskites Ba2YRuO6, Ba2YReO6,Ba2YOsO6, Ba2MgReO6, Ba2ZnReO6, Ba2Y2/3ReO6, Ba2MgOsO6, Ba2ZnOsO6, Ba2CdOsO6, La2LiRuO6, and La2LiOsO6. These compounds were prepared as powders using conventional solid state techniques. Structural characterization was performed with room temperature powder x-ray diffraction, and for most compounds, room temperature and low temperature powder neutron diffraction. The double perovskites in this investigation can be categorized as cubic Fm-3m and monoclinic P21/n. Over the ranges of temperatures measured, no space group changes were detected. Magnetic susceptibilty, magnetic hysteresis, and heat capacity measurements revealed a variation of ground states and magnetism across this selection of double perovskites. Inelastic neutron scattering experiments gave evidence for spin gap formation in almost all of the compounds.