Antiferromagnetic resonance in Bi2CuO4 single crystals

The angle and temperature dependences of AFMR in tetragonal easy plane Bi2C uO4 antiferromagnet with T-N = 42.5 K are investigated. The angle dependenc es of the resonance field measured at T = 4.2 K and omega = 9 GHz confirm t he assumption that due to the tetragonal crystal symmetry the spin-flop tra nsition in basal plane occurs when the magnetic field is aligned along hard axis but not easy one. The temperature dependence of effective anisotropy field in basal plane is determined by the four spin exchange interaction. T he resonance properties of Bi2CuO4 single crystal were proved to be strongl y sensitive to the oxygen nonstoichiometry. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.