The experimental study of dynamic thermal expansion of Bi-based high Tc superconductors

In this work, we have measured the dynamic process of thermal expansion (DPTE) of some Bi-based high-T-c superconductor samples in the temperature range 80 similar to 130K and found that the dynamic thermal expansion of Bi-based superconductor samples (Bi2Sr2Ca2Cu3Oy (T-c = 105K) and Bi1.8Pb0.4Sr2Ca2Cu3.15Ge0.05Oy (T-c = 102K)) change suddenly across T-c. The mechanism of this phenomenon is left to be studied.