INTERNAL-FRICTION AND SHEAR MODULUS OF BI SMUTH CERAMICS AT T-LESS-THAN-T(C)

The low frequency internal friction and the shear modulus are studied on bismuth ceramics at different deformation amplitudes in the tempera ture range 4,2-300 K. On the transition to the superconducting state t he internal friction background, the nonmonotonous character of the te mperature dependence of the shear modulus and the low-temperature anom aly (T congruent-to 0,3T(c)) of the internal friction are found to cha nge. The results obtained evidence for the loss of strength of the bis muth ceramics at T < T(c) and for the similarity of the inelastic defo rmation processes occuring in the superconducting state of low-T(c) an d high-T(c) superconductors.