OXYGEN DIFFUSION AND DEFECT MECHANISM IN C-AXIS TEXTURED THIN-FILMS OF YBA2CU3O7-X BY RESISTIVITY MEASUREMENTS

Isothermal resistivity measurements have been carried out to study the dynamics of oxygen out-and in-diffusion in thin films of YBa2Cu3O7-x in the temperature range 648-773 K. The activation energies for the ou t-and in-diffusion were determined to be 1.36 and 0.7 eV respectively. We have modelled the resistance-time plots for the oxygen in-diffusio n using an equation for one dimensional diffusion into a plane. The mi crostructural defects such as low angle grain boundaries associated wi th the c-axis oriented grains are believed to provide the required dif fusion paths in thin films of YBCO.