Crystal growth, structure and magnetic properties of the double perovskites Ln{sub 2}MgIrO{sub 6} (Ln=Pr, Nd, Sm-Gd)

Single crystals of double-perovskite type lanthanide magnesium iridium oxides, Ln{sub 2}MgIrO{sub 6} (Ln=Pr, Nd, Sm-Gd) have been grown in a molten potassium hydroxide flux. The compounds crystallize in a distorted 1:1 rock salt lattice, space group P2{sub 1}/n, consisting of corner shared MO{sub 6} (M=Mg{sup 2+} and Ir{sup 4+}) octahedra, where the rare earth cations occupy the eight-fold coordination sites formed by the corner shared octahedra. Pr{sub 2}MgIrO{sub 6}, Nd{sub 2}MgIrO{sub 6}, Sm{sub 2}MgIrO{sub 6}, and Eu{sub 2}MgIrO{sub 6} order antiferromagnetically around 10-15 K. - Graphical abstract: A SEM image of a typical crystal of Ln{sub 2}MgIrO{sub 6}, which forms in the monoclinic double perovskite structure, is shown.