Magnetic order in a metal thiocyanate perovskite-analogue

Abstract

Metal thiocyanate perovskite-analogues are a growing class of materials, but although they contain paramagnetic cations there have been no reports of their magnetic properties. Due to the large separations between the paramagnetic cations, with a shortest through-bond distance of 15.1 Å, these materials might be expected to be good examples of paramagnets. In this communication we investigate the magnetic properties of a metal thiocyanate framework Cr[Bi(SCN)₆]·xH₂O. We find that Cr[Bi(SCN)₆]·xH₂O undergoes long-range magnetic order at T_N = 4.0(2) K. We use neutron powder diffraction to determine that Cr[Bi(SCN)₆]·xH₂O has a MnO-type {111}_cubic-ordering as its ground state, consistent with frustrated nearest- and next-nearest-neighbour antiferromagnetic interactions. This suggests that appropriate design of metal thiocyanate perovskite-analogue structures may reveal a rich vein of frustrated magnetism.