Choice of insulating layer for YBCO in a multilayer architecture on bufferedRABiTS

Abstract

The choice of insulating layer for a YBCO/insulator multilayer architectureon buffered RABiTS was investigated. Double YBCO layers separated bySrTiO3 (STO) insulating layers were deposited by PLD. The STO architecture exhibited a highTc, small transition width and small out-of-plane and in-plane FWHM values. Fromsurface morphology and microtextural analysis of STO/YBCO multilayerarchitecture, no high-angle grain boundaries were observed and most of thegrains were well connected by boundaries with a misorientation of less than10°. Scanning transmission electron microscopy (STEM) was further used to show that theinterfaces of STO/YBCO/STO/YBCO on buffered NiW were clean and sharp. No chemicaldiffusion was observed between any interfaces and YBCO layers grew epitaxially.SrTiO3 is shown to be a good candidate to separate YBCO layers in a multilayer architecture forthe coated conductor cylinder approach and the replacement of thick YBCO single layersfor conventional tapes.