SUPERCONDUCTIVITY AND TRANSPORT BEHAVIOR OF LASER-ABLATED AU-ADDED YBA2CU3O7-DELTA THIN-FILMS

We report here a systematic investigation of superconducting propertie s of Au-added YBa2CU3O7-delta(YBCO) thin films in situ grown by pulsed laser ablation method. Films are highly c-axis oriented while the cor responding bulk samples contain multiphases. The superconducting trans ition temperature T-c of films remains close to 90 K even for large co ncentration of Au (up to 10% by weight) and the critical current denis ty J(c) is about 5X10(6) A cm(-2) at 77 K (in self-field) with higher reproducibility when compared with that of undoped films of YBCO on [1 00] LaAlO3. Preliminary investigations indicate that Au gets rejected by the grains and dopes the grain boundaries thus improving the stabil ity of the boundaries and hence of the films. Our result also demonstr ates that pulsed laser deposition can be used to grow films of compoun ds that generally do not form as a single phase in bulk by the convent ional solid state methods and hence offers unique possibilities in ter ms of exploring structure-property relationships in thin films. (C) 19 96 American Institute of Physics.