摘要
We measured the time decay of the magnetic moment of high Tc supercon-ductors YBa_(2)Cu_(3)O_(7-δ);ceranic samples and found the memory effect which has hitherto been reported ouly in single crystals.The temperature and feld ranges,especialy the memory time are diferent from those of the latter.We believed that the memory phenomenon in ceramic samples at liquid nitrogen temperature can only be understood in a combined picture of both fux creep and glass behaviour.
基金
Supported by the National Center of China for Research and Development on Supereonductivity.
