CaMg2N2 – ein gemischtes Erdalkalimetallnitrid mit anti-La2O3-Struktur / CaMg2N2 – a Mixed Alkaline-Earth Metal Nitride with anti-La2O3 Structure

Abstract

CaMg2N2 (trigonal, P3̄ m 1 (Nr. 164); a = 354.046(1), c = 609.079(2) pm; Z = 1) is isotypic to the anti-La2O3 structure with octahedral and tetrahedral coordination for Ca2+ and Mg2+ ions, respectively. The compound has been prepared by the reaction o f the binary nitrides Ca3N2 and Mg3N2 (molar ratio 1:2) in a tungsten crucible under a pure nitrogen atmosphere at 1050 °C. The formation of the solid CaMg2N2 may be interpreted in analogy to reactions o f related oxides as an acid-base reaction between the binary nitrides with different coordination tendencies of Ca2+ and Mg2+ ions. An analysis of the binary aristotype anti-La2O3 indicates that this structure is predisposed for building ternary phases.