Strong Localization Effect of Oxygen Deficiency on Carriersin T1 Based Superconductors  

作　　者：MA Qingzhu WANG Yunbo LI Yang CAO Guohui(Department of Physics, USTB, Beijing 100083, China Department of Materials Physics, USTB)(Laboratory of Nuclear Analysis Techniques Academia Sinica National Laboratory of Superconduchvity, Academia Sinica) 

出　　处：《International Journal of Minerals,Metallurgy and Materials》1997年第1期54-57,共4页矿物冶金与材料学报（英文版）

摘　　要：Investigation on the effect of Fe-doped T1-1223 superconductors has been carried out by the simultaneousmeasurements of the spectra of positron annihilation lifetime and Doppler broadening of position annihilation,together with the measurement of Hall coefficient. The results of samples with different doping level show that theoccupation of Fe atoms on Cu sites results in a linear decrement of superconducting transition temperature. The electron concentration in Cu-O layer has been enhanced by Fe doping. The difference in valence between Fe3+ andCu+ induces extra oxygen into the lattice and forms the extra oxygen defects. This Fe dopant leads to a stronglocalization of the electrons in the Cu-O layer. So the decrement of the concentration of the itinerant electronsresults in a decline of the superconducting transition temperature.Investigation on the effect of Fe-doped T1-1223 superconductors has been carried out by the simultaneousmeasurements of the spectra of positron annihilation lifetime and Doppler broadening of position annihilation,together with the measurement of Hall coefficient. The results of samples with different doping level show that theoccupation of Fe atoms on Cu sites results in a linear decrement of superconducting transition temperature. The electron concentration in Cu-O layer has been enhanced by Fe doping. The difference in valence between Fe3+ andCu+ induces extra oxygen into the lattice and forms the extra oxygen defects. This Fe dopant leads to a stronglocalization of the electrons in the Cu-O layer. So the decrement of the concentration of the itinerant electronsresults in a decline of the superconducting transition temperature.

关 键 词：positron annihilation T1 based superconductors oxygen defect 

分 类 号：TG111[金属学及工艺—物理冶金]