Synthesis and Magnetic Characterization of Geometrically Frustrated Double Perovskites

Geometric magnetic frustration occurs when magnetic ions are arranged spatially such that magnetic order is inhibited. Frustrated materials are of interest to the research community due to their rich magnetic phase diagrams, exhibiting exotic physics and high sensitivity to parameters such as doping and structural distortion. We have successfully synthesized and performed SQUID susceptibility measurements on the following 4d¹ and 5d¹ (Mo⁵⁺/W⁵⁺) double perovskite compounds: Ba₂YbMoO₆, Ba₂LuWO₆, Ba₂YWO₆, Ba₂ScMoO₆, and Sr₂ScMoO₆
Double perovskites exhibit frustration in the presence of antiferromagnetic correlations, and the nature of magnetic interactions may be determined by fitting the susceptibility data. In our measurements, all five compounds exhibited Curie-Weiss behavior with large and negative Curie-Weiss temperatures indicative of antiferromagnetic correlations. No evidence of magnetic order was found to 2K, indicating high frustration indices as seen in spin-singlet candidates such as Ba₂YMoO₆ and Ba₂LuMoO₆.