C. Filip et al., MAGNETIC-INTERACTIONS BETWEEN GD IONS IN GDXY1-XBA2CU3O7-DELTA - AN ESR INVESTIGATION, Physica. B, Condensed matter, 222(1-3), 1996, pp. 16-30
We analyse the ESR line width of Gd in GdxY1-xBa2Cu3O7-delta as a func
tion of the Gd concentration x and temperature in the normal state. Th
e powder samples were oriented in a magnetic field of 7 T. An orientat
ion dependence of the line width was found. The experimentally observe
d change of the ESR line width with Gd concentration x is compared wit
h a model calculation based on the Gd-spin dipole-dipole and exchange
interaction. The absence of resolved fine-structure splitting is expla
ined by a dominance of the dipole-dipole and exchange interaction.