Magnetic properties of Cu2V2O7

Magnetic measurements were performed on Cu2V2O7. Above similar to 70K param agnetic susceptibility obeys the Curie-Weiss law. Value of effective magnet ic moment mu(eff) = 1.9 mu(B) corresponds to that of Cu2+. The Weiss temper ature Theta = - 66 K is negative and indicates an antiferromagnetic exchang e interaction between Cu2+ ions. At T-c = 35 K a spontaneous magnetization arises due to the transition from paramagnetic state into either ferrimagne tic or canted antiferromagnetic state. (C) 2000 Published by Elsevier Scien ce B.V. All rights reserved.