Thermodynamics properties of NiCuP4O12

The variation of magnetic susceptibility and heat capacity with temperature for the bimetallic nickel Ni(II)-copper Cu(II) cyclo-tetrametaphosphates (CuNiP4O12) has been examined. The complex has a structure of quasi-one-dimensional alternate spins chains of Ni(II) and Cu(II) that exhibits a three-dimensional magnetic ordering at approximately 13.5 K. The compound is characterized by a ferromagnetic intrachain constant JF=4.05 K, with a significant effect of single ion anisotropy D=9.70 K. The chains are weakly coupled antiferromagnetically with an interchain exchange constant of 2zAFJAF=−1.125 K.