Abstract

The MPX3 (M=transition metal, X=S,Se) family of compounds have layered structures, with atomic planes that are weakly bound by van der Waals forces. This puts them in the same class of materials as graphite, and they share further similarities as, like graphite, the metal atoms form a honeycomb lattice in the strongly bound atomic planes.

Their electronic and optic properties have been extensively studied, as well as the potential for interplanar intercalation, as they have potential applications as semiconductors, photorefractive materials, and battery applications. Their magnetic properties, however, have been largely overlooked. This is a pity, because members of the family are excellent physical representations of model magnetic systems. Furthermore, changing the metal cation results in a significant change in the type of model magnetism, making the family an excellent test bed for the study of magnetic anisotropy and frustration.

This presentation will discuss work on the magnetic structure and dynamics of the MPS3 members of the family, showing the significant errors in previously established results and highlighting recent surprising discoveries, including multiferroic behaviour and unusual critical dynamics.