HIGH CRITICAL-CURRENT DENSITY IN EPITAXIAL HGBA2CACU2OX THIN-FILMS

High quality superconducting HgBa2CaCu2Ox (Hg-1212) thin films have be en reproducibly fabricated using cation-exchange method. The thin film s have pure Hg-1212 phase and have smooth surface morphology. The supe rconducting transition temperatures of these films are in the range of 120-124 K. The critical current density J(c) is up to 3.2 x 10(6) A/c m(2) at 77 K and drops only by a factor of 2 at 100 K and self field. At 110 K, a J(c) of 7.8 x 10(5) A/cm(2) has been obtained. X- ray diff raction pole figures show that these films are epitaxially grown on La AlO3(001) substrates, which is consistent with a chi(min) of 19% obtai ned using Rutherford backscattering/channeling analysis. (C) 1998 Amer ican Institute of Physics. [S0003-6951(98)03046-0].