ANOMALOUS BEHAVIOR OF BI-SYSTEM SUPERCONDUCTORS IN THE NORMAL-STATE AND THEIR CORRELATION WITH SUPERCONDUCTIVITY

Our experiments show that Bi-system samples exhibit two parameter anom alies and two heat and weight anomalies in normal state. For the sampl es of (Bi,Pb)(2)Sr2CaCu2Oy, as the superconducting volume is over 65%, two anomalies of heat and weight at about 400 degrees C and 750 degre es C, respectively, are significantly observed; as the superconducting volume of the samples is under 50%: or the samples are non-supercondu cting the anomaly at about 400 degrees C is hardly observed. For the s amples of (Bi,Pb)(2)Sr2Ca2Cu3Oy, as the superconducting volume is over 65%, they exhibit two anomalies at about 300 degrees C and 750 degree s C, respectively; as the superconducting volume is under 50%, the ano maly at about 300 degrees C disappears, and as the samples are non-sup erconducting it shows a quite opposite behavior to the superconducting samples at about 300 degrees C. We develop a computer program based o n calculation of lattice energy to simulate the experimental results, it is found that the change of the lattice energy can well explain the anomalous phenomena in the samples.