EPR and magnetization studies on single crystals of a heterometallic (Cu|| and Cr|||) complex: zero-field splitting determination

Magnetic properties of single crystals of the heterometallic complex [Cu(bpy)3]2[Cr(C2O4)3]NO3 9H2O (bpy = 2, 2'-bipyridine)have been investigated. From the recorded EPR spectra, the spin-Hamiltonian parameters have been determined. The magnetization measurements have shown magnetic anisotropy at low temperatures, which has been analysed as a result of the zero-field splitting of the CrIII ion. By fitting the exactly derived magnetization expression to the measured magnetization data, the axial zero-field splitting parameter, D, has been calculated. Comparing to the EPR measurements, it has been confirmed that D can be determined from the measurements of the macroscopic magnetization on the single crystals