Improved properties of Pulsed Laser Deposited YBaCuO on NdGaO3 using CeO2 template layers

Abstract

NdGaO3 (NGO) is, due to its low loss characteristics, a favourite substrate for high frequency applications [1]. However, problems occur when trying to deposit high quality YBaCuO layers on top of it. The optimum deposition temperature during pulsed laser deposition to obtain highTc, high critical current values andc-axis orientation on NGO is significantly higher than for standard substrates, like SrTiO3 or YSZ. A disadvantage of this high deposition temperature is the quality of the film surface. The number of outgrowths and precipitates increases rapidly at higher temperatures. To improve the quality of the layers, the effect of a CeO2 template layer was investigated, leading to remarkable and very promising results. In this paper we focus on the orientation as well as on the surface morphology with and without a CeO2 template layer on NGO. The orientations were analysed with XRD, the surface morphology with SEM and STM/AFM.