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Free keywords:
nitrides, complex metallic alloys, Crystal structures, Magnetic properties
Abstract:
Two new calcium nitridomanganates, Ca12[Mn19N23] (P3, a = 11.81341(3) Å, c = 5.58975(2) Å, Z = 1) and Ca133[Mn216N260] (P‐3, a = 39.477(1) Å, c = 5.5974(2) Å, Z = 1), were obtained by a gas‐solid reaction of Ca3N2 and Mn with N2 at 1273 K and 1223 K, respectively. The crystal structure of the former compound was determined from high‐resolution X‐ray synchrotron powder diffraction data, whereas single‐crystal X‐ray diffraction was employed to establish the crystal structure of the latter phase, which classifies as a complex metallic alloy (CMA). Both crystal structures possess 2D nitridomanganate layers containing similar building blocks but of different levels of structural complexity. Bonding analysis as well as magnetic susceptibility and electron spin resonance measurements revealed that only a fraction of Mn atoms in both structures carries a localized magnetic moment, while for most Mn species the magnetism is quenched due to metal‐metal bond formation.
