Ca12 [Mn19 N23 ] and Ca133 [Mn216 N260 ]: Structural Complexity by 2D Intergrowth

Alexander Ovchinnikov; Matej Bobnar; Yurii Prots; Horst Borrmann; Jörg Sichelschmidt; Yuri Grin; Peter Höhn

doi:10.1002/anie.201804369

Ca₁₂ [Mn₁₉ N₂₃ ] and Ca₁₃₃ [Mn₂₁₆ N₂₆₀ ]: Structural Complexity by 2D Intergrowth

Angew Chem Int Ed Engl. 2018 Sep 3;57(36):11579-11583. doi: 10.1002/anie.201804369. Epub 2018 Aug 6.

Authors

Alexander Ovchinnikov^{1

2}, Matej Bobnar¹, Yurii Prots¹, Horst Borrmann¹, Jörg Sichelschmidt¹, Yuri Grin¹, Peter Höhn¹

Affiliations

¹ Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Strasse 40, 01187, Dresden, Germany.
² Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA.

PMID: 29897653
DOI: 10.1002/anie.201804369

Abstract

Two new calcium nitridomanganates, Ca₁₂ [Mn₁₉ N₂₃ ] (P3, a=11.81341(3) Å, c=5.58975(2) Å, Z=1) and Ca₁₃₃ [Mn₂₁₆ N₂₆₀ ] (P3‾ , a=39.477(1) Å, c=5.5974(2) Å, Z=1), were obtained by a gas-solid reaction of Ca₃ N₂ and Mn with N₂ at 1273 K and 1223 K, respectively. The crystal structure of Ca₁₂ [Mn₁₉ N₂₃ ] 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 Ca₁₃₃ [Mn₂₁₆ N₂₆₀ ] phase, which classifies as a complex metallic alloy (CMA). Both crystal structures have 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 the Mn atoms in both structures carries a localized magnetic moment, while for most Mn species the magnetism is quenched as a result of metal-metal bond formation.

Keywords: calcium; complex metallic alloys; magnetic properties; manganese; nitrides.