Fabrication of Tl-2212 superconducting thin films by a two-step procedure with post-annealing in a closed container

Abstract

Highquality Tl2Ba2CaCu2Oy(Tl2212) thin films were prepared on s ingle crystal(001) lanthanum aluminate (LaAlO3) substrates by a twostep method. Tlfree amor phous precursor films were first deposited by a pulsed laser deposition techniqu e and then the thalliation, crystallization and oriented growth of the films wer e obtained in the process of annealing treatment in a sealed high-temperature st eel capsule at temperature of 720—850℃ . Xray diffraction reflections reveal th e existence of only Tl2212 phase with nearly perfect caxis orientation. The fu ll width at half maximum of ω scan of (0012) peak was 072°. Scanning electro n m icrographs of the thin films show that the surfaces of the films are smooth. The zeroresistance transition temperature TC0 is 1062K.