Superconducting YBa2Cu3O7 thin films on MgO by KrF laser ablation: Optimization of deposition parameters

Abstract
The optimization of interrelated deposition parameters during deposition of in situ YBa2Cu3O7 thin films on MgO 〈001〉 substrates by KrF laser ablation was systematically studied in a single experimental chamber. The optimum condition was found to be a substrate temperature of 720 °C and a target‐substrate distance of 5 cm in an oxygen partial pressure of 100 mTorr. These conditions produced films with Tc = 87 K. The presence of YO in the plasma plume was found to be important in producing good quality films. The films were characterized by resistance‐temperature measurements, energy dispersive x‐ray analyses, scanning electron microscopy, and x‐ray‐diffraction measurements, and the physical reasons underlying film quality degradation at parameter values away from optimal are discussed.