Preparation and properties of superconducting thin films by excimer laser ablation.

摘要

Excimer laser ablation with an in situ heat treatment was used to prepare high quality superconducting YBa(sub 2)Cu(sub 3)O(sub 7(minus)x) thin films on (100)-SrTiO(sub 3) and (100)-LaAlO(sub 3) substrates. A pulsed excimer laser (XeCl; 308 nm) was used to ablate a rotating, bulk YBa(sub 2)Cu(sub 3)O(sub 7(minus)x) target at a laser energy density of 2--3 J/cm(sup 2). Based on four-probe dc resistance measurements, the films exhibited superconducting transition temperatures ((Tc), midpoint) of 88 and 87K with 2K (90 (minus) 10%) transition widths for SrTiO(sub 3) and LaAlO(sub 3), respectively. Transport critical current densities (J(sub c)) measured at 77K were 2 (times) 10(sup 6) and 1 (times) 10(sup 6) A/cm(sup 2) in zero field for SrTiO(sub 3) and LaAlO(sub 3), respectively. X-ray diffraction (XRD) analysis showed the films to be highly oriented, with the c-axis perpendicular to the substrate surface. 11 refs., 5 figs. (ERA citation 15:034978)