Magnetic Properties of Cu₃(TeO₃)₂Br₂with Spin 1/2 Diamond Lattice

Abstract

Magnetic studies have been carried out on Cu 3 (TeO 3 ) 2 Br 2 with diamond lattice of spin 1/2 Cu 2+ ions. By using the high temperature expansion of the magnetic susceptibility, the exchange coupling constants have been determined to be J 1 / k B =280±4 K (antiferromagnetic) and J 2 / k B =-23±1 K (ferromagnetic) for two kinds of Cu–Cu pairs formed by the connections with edge and diagonal lines of a diamond, respectively. It indicates that each diamond chain has the ferrimagnetic state in the reported phase diagram [Takano et al. : J. Phys.: Condens. Matter 8 (1996) 6405]. The observed magnetic behavior can be well understood by this characteristic. Because J 2 is ferromagnetic, the present system does not have magnetic frustration effects.