Chemical Vapor Transport Synthesis of Cu(VO)₂(AsO₄)₂ With Two Distinct Spin-1/2 Magnetic Ions

Abstract

A new copper vanadyl arsenate, Cu(VO)2(AsO4)2, was synthesized via the chemical vapor transport method. Cu(VO)2(AsO4)2 adopts an original structure type. It is characterized by layers formed by edge-sharing and corner-sharing V-centered octahedra resulting in a unique topology that was hitherto not reported for vanadates. Single CuO6 octahedra connect vanadate layers into a rigid framework. The thermal expansion of the framework studied by the single-crystal HT X-ray diffraction is reported. The magnetic behavior of Cu(VO)2(AsO4)2 shows an interplay of ferromagnetic V4+–V4+ and antiferromagnetic Cu2+–V4+ interactions that result in a ferrimagnetic long-range order below T C = 66 K.