Epitaxial Order and Resistivity of High Temperature Superconductors Grown on SrTiO sub 3 .

Thin films of YBa sub 2 Cu sub 3 O sub (7-delta) grown on 001>- oriented SrTiO sub 3 substrates attain zero resistance at a temperature of T=92K and have a superconducting critical current, j sub c , of more the 3X10 sup 6 Acm sup (-2) at T=77K. A low resistivity superconducting Cu-rich phase shows great promise for epitaxial growth on SrTiO sub 3 substrates because of an improved lattice match in the growth direction and strong epitaxial ordering due to the presence of the new phase.