MöSSBAUER STUDY ON Eu-Ba-Cu OXIDE SUPERCONDUCTOR

Onset of superconductivity of the new high T_c superconductor Eu-Sa-Cu-O was found to be 92K. The valence of Eu ion and the Debye temperature of this superconductor were determined using Mössbauer spectroscopy. The experimental results show abnormal changes of isomer shift and lattice-softening nearby the transition temperature T_c. It seems that high Debye temperature is not a necessary condition for this high T_c superconducting system.