AMX3 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, TC=8.5(1)K) and CsCo(NCS)3 (TC=6.7(1)K) order as weak ferromagnets. On the other hand, CsMn(NCS)3 orders as an antiferromagnet (N\'eel temperature, TN=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.
@article{arxiv.2301.03880,
title = {Non-collinear magnetism in the post-perovskite thiocyanate frameworks CsM(NCS)$_3$},
author = {Madeleine Geers and Jie Yie Lee and Sanliang Ling and Oscar Fabelo and Laura Cañadillas-Delgado and Matthew J. Cliffe},
journal= {arXiv preprint arXiv:2301.03880},
year = {2023}
}