YBCO系超导陶瓷的掺杂研究

本文研究了掺杂 SnO_2对 YBCO 系超导陶瓷的制备工艺、烧结机制、显微结构及超导电性等的影响.结果表明适量 SnO_2掺杂有助于材料致密化,改善材料的烧结质量,且可显著提高该系材料的临界电流密度,文章对此作了初步讨论.     

POSITRON ANNIHILATION STUDY OF YBa2(Cu1-xSnx)3Oy SUPERCONDUCTORS

The positron annihilation lifetime spectra and their temperature dependence for the YBa₂Cu₃O_y superconducting ceramics doped with Sn have been studied. The resutts of analyses indicate that the element Sn is substituted for Cu(1) sites, and this leads to the ordering of the oxygen atoms as well as the increase of local electronic density in the Cu(1)-O layer where Cu(1) is substituted by Sn.     

POSITRON ANNIHILATION STUDY OF YBa2(Cu1-xSnx)3Oy SUPERCONDUCTORS

The positron annihilation lifetime spectra and their temperature dependence for the YBa₂Cu₃O_y superconducting ceramics doped with Sn have been studied. The resutts of analyses indicate that the element Sn is substituted for Cu(1) sites, and this leads to the ordering of the oxygen atoms as well as the increase of local electronic density in the Cu(1)-O layer where Cu(1) is substituted by Sn.     

POSITRON ANNIHILATION STUDY OF YBa2(Cu1-xSnx)3Oy SUPERCONDUCTORS

The inelastic-tunneling model can be used to explain the linear conductance background observed in tun-neling in the high-T_c oxide super conductors. Introducing a parameter into the tunneling Hamiltanian to describe the strength of on-site Coulomb repulsion, we have derived an expression for the inelastic-tunneling conductance. We further discuss what form of the spin-fluctuation propagators in the inelastic-tunneling model can produce the linear tunneling conductance which would agree well with the experimental data.