High-Pressure Synthesis and Magnetic Properties of Layered Double Perovskites Ln₂CuMO₆ (Ln = La, Pr, Nd, and Sm; M = Sn and Zr)

Ln 2 CuSnO 6 (Ln = Pr, Nd, and Sm) and La 2 CuZrO 6 have been stabilized in the same layered double perovskite structure as La 2 CuSnO 6 at high pressures of 6−8 GPa. Their crystal structures and magnetic properties were investigated. Replacement of La 3+ by smaller lanthanide ions and Sn 4+ by larger Zr 4+ increased the buckling of the Cu−O−Cu bonds in the CuO 2 layers. In Nd 2 CuSnO 6, both the Cu and Nd sublattice were found to exhibit weak ferromagnetism owing to spin canting. The magnetization data showed an anomalous transition at 110 K.