Highly anisotropic 1/3-magnetization plateau in a ferrimagnet Cs2Cu3(SeO3)4·2H2O: topology of magnetic bonding necessary for magnetization plateau

Abstract

We prepared Cs₂Cu₃(SeO₃)₄·2H₂O composed of Cu²⁺ ions at square-planar coordination sites and characterized its structural and magnetic properties, to show that Cs₂Cu₃(SeO₃)₄·2H₂O is a ferrimagnet exhibiting a highly anisotropic 1/3-magnetization plateau. This unprecedented anisotropy in a magnetization plateau is the consequence of three effects, namely, the orthogonal arrangements of the corner-sharing CuO₄ square planes, the nearest-neighbour antiferromagnetic exchange, and the anisotropic g-factor of the Cu²⁺ ions at square-planar coordination sites. By analyzing the topology of magnetic bonding, we found why magnetic plateaus are observed only for certain ferrimagnets and antiferromagnets.