Crystal structure and ferrimagnetism of AgCoCr(MoO) with mixed occupation of the transition metal sites.

We prepared a new compound, AgCoCr(MoO), and characterized its crystal structure and physical properties. It crystallizes in the triclinic space group 1̄ with mixed occupation of the transition-metal sites M = (Co and Cr). The Ag site is split into three close positions. The magnetic subsystem of the title compound consists of MO dimers and MO trimers, made up of edge-sharing MO octahedra. These units are interconnected by MoO tetrahedra. Both and magnetic susceptibility, as well as specific heat and dielectric permittivity, evidence a ferrimagnetic behavior below = 5.5 K. To investigate the properties of this nanostructured system, we evaluated spin exchanges for the four most probable magnetic ion arrangements. We found that considering the local structure is essential for understanding the behavior of a magnet with mixed occupation of the transition metal sites.