Single crystal synthesis and magnetism of the BaLn$_{2}$O$_{4}$ family (Ln$=$lanthanide)

The BaLn$_{2}$O$_{4}$ family (Ln$=$La-Nd, Sm, Gd-Yb) has been synthesized for the first time in single crystalline form using a novel metal flux method. The family crystallizes in the CaV$_{2}$O$_{4}$ structure with quasi-one-dimensional zigzag chains of lanthanides, and we present a study of the structure details as the lanthanide goes from La to Yb. Magnetic susceptibility measurements on the series reveal that, while one analog (Gd) orders at low temperatures, some of the others (Tb, Ho, Nd) display magnetic anomalies. Some of the analogs (Ce, Tb, Nd, Yb) exhibit a susceptibility that clearly deviates from the Curie-Weiss behavior, due to crystal field effects. In general, the series display geometrically frustrated antiferromagnetic interactions.