Non-collinear magnetism in the post-perovskite thiocyanate frameworks CsM(NCS)

• Published in: Chemical science (Cambridge) Vol. 14; no. 13; pp. 3531 - 354
• Main Authors: Geers, Madeleine, Lee, Jie Yie, Ling, Sanliang, Fabelo, Oscar, Cañadillas-Delgado, Laura, Cliffe, Matthew J
• Format: Journal Article
• Language: English
• Published: 29.03.2023
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d2sc06861c

AMX 3 compounds are structurally diverse, a notable example being the post-perovskite structure which adopts a two-dimensional framework with corner- and edge-sharing octahedra. Few molecular post-perovskites are known and of these, none have reported magnetic structures. Here we report the synthesis, structure and magnetic properties of molecular post-perovskites: CsNi(NCS) 3 , a thiocyanate framework, and two new isostructural analogues CsCo(NCS) 3 and CsMn(NCS) 3 . Magnetisation measurements show that all three compounds undergo magnetic order. CsNi(NCS) 3 (Curie temperature, T C = 8.5(1) K) and CsCo(NCS) 3 ( T C = 6.7(1) K) order as weak ferromagnets. On the other hand, CsMn(NCS) 3 orders as an antiferromagnet (Néel temperature, T N = 16.8(8) K). Neutron diffraction data of CsNi(NCS) 3 and CsMn(NCS) 3 , show that both are non-collinear magnets. These results suggest molecular frameworks are fruitful ground for realising the spin textures required for the next generation of information technology. The synthesis, structure and magnetic properties of the layered molecular post-perovskites CsM(NCS) 3 M = Ni, Mn, Co, are reported. Neutron diffraction and bulk magnetometry show these isomorphic compounds order with different complex non-collinear magnetic structures.