SUPERCONDUCTING PROPERTIES OF ORIENTED YBA2CU3O7-X FILMS ON MGO AND SRTIO3 SUBSTRATES

Abstract

Using single-target sputter deposition, the c-axis oriented YBa2Cu3O7-x films can be obtained on both MgO and SrTiO3 substrates by appropriately controlling the substrate temperature at 700-degrees-C. However, on examining a.c. susceptibility and electrical dissipation, we find that the films on a SrTiO3 substrate possess better superconducting properties, such as a stronger coupling between the superconducting grains; a higher potential energy for flux pinning; and a larger capacity for current conduction. Also, from the magnetization hysteresis measurement, the critical current density of 2.6 x 10(6) A cm-2 (77 K) and 4.5 x 10(7) A cm-2 (5 K) for the sample on the SrTiO3 substrate can be estimated.