Inverse perovskites (RE3N)Sn with RE = La, Ce, Pr, Nd, Sm: Preparation, crystal structures and physical properties

Abstract

The ternary compounds (RE3N)Sn with RE = La, Ce, Pr, Nd, Sm were prepared starting from the elements. The compounds with RE = La, Ce, Pr were obtained as single phase materials according to X-ray powder diffraction patterns, which also indicate the cubic inverse perovskite crystal structure (space group Pm3m, La: a = 509.48(2) pm, Ce: a = 501.59(2) pm, Pr: a = 497.53(2) pm, Nd: a = 494.70(5) pm, Sm: a = 488.35(9) pm). Chemical analyses proof the correct composition and particularly the absence of nonmetallic constituents next to nitrogen. All studied compounds show metallic characteristics in the electrical resistivity. Magnetic susceptibility measurements indicate (La 3N)Sn to be a Pauli-paramagnet. Initially observed superconductivity was traced down to be due to thin La films on the surface of the grains. The Ce and Pr containing compounds show the behavior of 4f1 ions and 4f 2 ions, and order antiferromagnetically at 6.8(2) K and 48(1) K, respectively. © 2006 Verlag der Zeitschrift für Naturforschung.