MICROWAVE MAGNETOABSORPTIONS OF BI-2(CA,GD,BI)(3)CU2OZ SUPERCONDUCTOR

Microwave magnetoabsorptions were observed for a Bi-2(Ca,Gd,Bi)(3)Cu2O z superconductor over a temperature range from 6 K to room temperature . A broad absorption slope of Gd3+ was observed with the external stat ic field from 0 to 6 kOe, because a weak antiferromagnetic order occur red in the Gd3+ sublattice. When each particle is small in a powder sp ecimen, a usual ESR line of Gd3+ was observed due to superparamagnetis m. Nonresonant microwave absorptions due to superconductivity were obs erved below 56 K, and the lower critical fields as well as the diamagn etic susceptibilities were determined.