Röntgenograpliische und magnetische Untersuchungen an perowskitverwandten Cyanoverbindungen CsMIIMIII(CN)6 / X-Ray and Magnetic Studies of Perovskite-Related Cyano Compounds CsMIIMIII (CN)6

Abstract

Abstract The perovskite-related cyano compounds CsMIICr(CN)6 (MII = Mn, Zn), CsZnFe(CN)6 and CsMnCo(CN)6 (Mn = Mn-Cu) are characterized by their IR active C - N and MIII-CN stretching frequencies, their lattice constants and their magnetic susceptibilities (4,2-295 K). Except for CsCuCo(CN)6, which is tetragonally distorted, all compounds crystallize cubically face-centered (with lattice constants in the range from 1020 to 1084 pm). The magnetic behaviour indicates low spin MIII and high spin MII states, supporting the IR evidence for a strictly ordered MIII-CN-MII arrangement. The compound CsMnCr(CN)6 is ferrimagnetic, with a Néel temperature of TN = 90 K and an extrapolated spontaneous magnetization of a = 2,30 μB at 0 K. Superexchange interactions via the cyano bridges are considered responsible for the ferrimagnetism observed.