High pinning potential in YBCO thin films deposited from a target prepared from YBCO nanopowder

Abstract

Thin YBa 2Cu 3O 6+ x (YBCO) films were prepared on SrTiO 3 substrates by pulsed laser deposition using a target made from nanosized powder. These films show high critical current densities J c≈1×10 7 A/cm 2 at 77 K in zero field as obtained by SQUID magnetization measurements. The pinning potentials, U( T), were calculated from the magnetic relaxation curves measured at several temperatures after cooling the sample in 1 T. From these data the U(0 K) was extrapolated to be 900 K, which is higher than previously reported for as-prepared films.