Characterization of thin films of Y-Ba-Cu-O on oxidized silicon with a zirconia buffer layer

Abstract

Thin films of the high-temperature superconductor Y-Ba-Cu-O with zero-resistance transition temperatures up to 83 K have been recently reported by using a zirconia buffer layer on the primary materials of interest for electronics, Si and SiO2. In this letter, various characteristics of these films are discussed. Microstructural analysis using transmission electron microscopy shows the complex morphology of the unoriented polycrystalline films. Elemental depth profiling by x-ray photoelectron spectroscopy shows the effectiveness of the zirconia buffer layer in preventing interdiffusion; fluorine is found throughout the film at an abundance of 4 at. % The critical current density was measured as a function of temperature; its value is 5 kA cm−2 at 4.2 K.