C. Filip et al., ESR INVESTIGATION OF THE EXCHANGE INTERACTION INVOLVING GD-IONS IN THE NORMAL-STATE OF Y1-XGDXBA2CU3O7-DELTA ORIENTED POWDERS, Physica. C, Superconductivity, 235, 1994, pp. 1645-1646
A theoretical analysis concerning the concentration dependence of the
exchange-narrowed Gd3+-ESR linewidth in Y1-xGdxBa2CU3O7-delta magnetic
ally oriented powders is presented. By comparing the theoretical predi
ctions with the experimental ESR linewidths, the exchange coupling con
stant, 2J, between Gd nearest-neighbour spins is estimated to be 2J =
-6 x 10(-3) meV.