Magnetic behavior of x(0.66CuO-0.34V2O5)•(1-x) As2O3 glasses

The x(0.66Cu0-0.34V(2)O(5)).(1-x)As2O3 vitreous system (xCVA) with x = 0.40, 0.50, 0.60 and 0.70 was investigated by magnetic susceptibility and electron paramagnetic resonance (EPR) measurements. Magnetic susceptibility measurements were performed using a Faraday-type balance in the temperature range: 80 to 300 K. EPR investigation was performed at room temperature at 9.4 GHz. EPR data show that magnetic properties of the xCVA glasses are determined by the presence of V4+ and CU2+ ions in the vitreous matrix. The magnetic susceptibility of these glasses obeys the Curie-Weiss law with negative Curie temperatures suggesting the presence of exchange interactions between the V4+ and CU2+ ions. Magnetic interactions between the V4+ and Cu2+ ions determine formation of antiferromagnetically coupled mixed TM ion pairs in the xCVA glasses. (C) 1998 Elsevier Science B.V.