Nanometer-sized non-superconducting particulates in superconductive REBCO
films, where RE is a rare earth metal, for flux pinning enhancement and a
method of forming are disclosed. A target with a second phase material
sector portion and a superconductive material portion is used in a pulse
laser deposition process to form films on substrates according to the
present invention. The films consist of 10-20 nm-sized precipitates. In a
0.5 .mu.m thick film, a transport critical current density (J.sub.c)>3
MA/cm.sup.2 at 77K in self-field was measured. In one embodiment,
magnetization J.sub.c at 77 K and 65K showed significant improvements in
a composite YBCO films with fine precipitates produced according to the
present invention as compared to non-doped (standard) YBCO films (>10
times increase at 9 T, 65 K).