In-situ growth of Li-doped Bi 2Sr 2CaCu 2O 8 thin films by laser deposition

Abstract

In-situ superconducting thin films of Li-doped Bi 2Sr 2CaCu 2O 8 have been prepared on MgO single-crystal substrates by a pulsed laser ablation technique. Among the different parameters studied, substrate temperature and oxygen pressure during the deposition have been found to be most important. Deposition at 600°C in 0.2 mbar oxygen pressure from an undoped target led to semiconducting films. The addition of lithium was investigated and, under the same conditions, critical temperatures of 65 K-70 K were obtained. For such films, critical current densities in excess of 10 4 A/cm 2 were measured at 50 K. These results demonstrate that Li-doping is effective for low-temperature in-situ processing of superconducting Bi-based films.