RESONANCE-TYPE INTERNAL-FRICTION OF A 1 1/1/2 BI-SR-CA-CU-O SUPERCONDUCTOR AT VERY LOW-FREQUENCIES/

The internal-friction (IF) technique is applied to study high-T(c) sup erconducting Bi-Sr-Ca-Cu-0 (BSCCO) system cuprates. IF measurements at five different frequencies from 10(-2) to 5 Hz in a temperature range from room temperature to 330-degrees-C are carried out. Resonance-typ e behaviour Of IF at a very low frequency (10(-2) Hz) appears once the sample is slightly deformed (epsilon congruent-to 10(-4)). The IF cha racteristic of the high-frequency side of the IF-frequency resonance p eak is thus determined. It is suggested that the resonance originates from two-dimensional defect vibration, and most probably the domain wa ll motion caused by dislocation translation.