Critical-current measurements in epitaxial films of YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/ compound

We have grown epitaxial films of the YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/ compound on SrTiO/sub 3/ substrates. The superconducting critical current in these films at 77 K is in excess of 10/sup 5/ A/cm/sup 2/ and at 4.2 K in excess of 10/sup 6/ A/cm/sup 2/.