Correlation between structural and superconducting properties in Tl-Ba-Ca-Cu-O thin films

Abstract

We have investigated a correlation between structural and superconducting properties by means of transport and microwave techniques in Тl1Ва2Са2Сu3Ох (Tl-(1223)) thin films on SrTiO3, LaAlO3 and MgO(lOO) substrates. Our Tl-(1223) thin films on SrTiO3 prepared by MOD method have a high Jc of 6.3X105A/cm2 at 77K in a zero magnetic field. When the magnetic field was applied perpendicular to the a-b plane, we have found that the field transport properties of the Tl-(1223) thin films were superior to those of the Tl-(2223) and Bi-(2223) thin films. Then the hysteretic effect of Jc in the magnetic field was not observed at 77K below 0.1T. Moreover, The surface resistance of the films on SrTiO3 and LaAlO3 substrates were lower than that of the film on MgO substrate at 78K using cavity perturbation technique. Because the films on SrTiO3 and LaAlO3 are highly c-axis oriented with good in-plane epitaxy with respect to the substrate.