Influence of the deposition rate on crystalline structure and cation disordering of YBCO thin films

We have systematically investigated the superconducting properties of in-situ deposited YBCO thin films as a function of the substrate temperature in the range 650-800/spl deg/C and the deposition rate in the range 0.1-12.2 nm/s. It was found that the cubic structure of YBCO grows at low substrate temperatures and high deposition rates. Also, expansion of the c-lattice parameter and decrease of the critical temperature of YBCO thin films were observed with decreasing substrate temperature and increasing deposition rate, suggestive of cation disordering in the YBCO thin films. These results are explained by cation kinetics.