Improvement of Upper Critical Field in YBa2Cu3Oy Films by Substituting 3d Metal for Cu Sites Using Combinatorial Pulsed-laser Deposition

S. Kojima, Y. Ichino, Y. Yoshida
2014 Physics Procedia  
It is well known that the critical upper field B c2 is improved by shortening of the coherence length owing to the scattering of electrons in a superconductor. In order to improve of B c2 in YBa 2 Cu 3 O y (YBCO) films in our study, we substituted 3d metals (M = Zn, Co, Ni, Fe) for the Cu sites of the YBCO films. We used combinatorial pulsed-laser deposition to fabricate different YBa 2 (Cu 1-x M x ) 3 O y films by continuously changing the amount of substitution metal x, from 0 to 0.01 on a
more » ... gle substrate using. As a result, the superconducting transition temperature T c and critical current density J c decreased with increasing amounts of all four variations of substitution metal M. For example, T c was 82.5 K and J c at 77 K was 0.15 MA/cm 2 in the Co-substituted sample with x = 0.0091. For the substitution of Co and Ni, we confirmed that B c2 was improved with increasing amount of substitute metal up to x = 0.01. Although B c2 (0 K) of a pure-YBCO film was 101 T, B c2 (0 K) of the Co-substituted sample with x = 0.0091 reached 272 T. On the other hand, the irreversibility field decreased by substituting Zn, Co, Ni, or Fe for Cu.
doi:10.1016/j.phpro.2014.09.015 fatcat:tdgz5dqtafcabpmyvctiu6qjpu