TBCCO/LAO高温超导薄膜的电阻转变和各向异性

Resistance transition and anisotropy of TBCCO/LAO high temperature superconducting thin films

摘要: 将Tl₂Ba₂CaCu₂O₈(TBCCO)高温超导薄膜通过磁控溅射的方法沉积到LaAlO₃(LAO)衬底上,SEM和XRD的测量结果显示该超导薄膜具有很高的成膜品质.通过标准四引线方法对TBCCO/LAO高温超导薄膜在不同磁场下的电阻转变进行了研究.结果表明:在一定的磁场下TBCCO/LAO超导薄膜具有很强的电阻转变展宽现象,并且当磁场垂直于超导薄膜表面时该超导薄膜显示出更强的电阻转变展宽现象.用热激活辅助磁通流动理论对该超导薄膜的电阻转变展宽现象进行了解释,同时通过分析超导薄膜的电阻转变对该超导薄膜的各向异性进行了讨论.

Abstract: Tl₂Ba₂CaCu₂O₈(TBCCO) films were deposited on LaAlO₃ (LAO) substrates by magnetron sputtering. The results of SEM and XRD show the films have high quality. The resistive transitions of the TBCCO/LAO were investigated at different magnetic fields using a standard four-probe method. The resistive transition broadening of TBCCO/LAO can be seen and it is stronger with the magnetic field perpendicular to the films than with the magnetic field parallel to the films. The thermally activated flux flow theory was used for analyzing the resistive transition broadening. The anisotropy of the films was discussed by analyzing the resistive transition.