TEM STUDY OF THE MICROSTRUCTURE AND INTERFACES IN YBa2Cu3Oy THIN FILMS GROWN ON SILICON WITH A Eu2CuO4/Y-ZrO2 BI-LAYER BUFFER

Abstract

The microstructures in the YBa 2 Cu 3 O y films grown on Eu 2 CuO 4/ Y-ZrO 2(YSZ) buffered silicon were studied by means of transmission electron microscopy. Our effort was emphasized on the influence of the interfacial microstructures on the formation and epitaxy of the grown layer. It was found that a native Si -oxide layer ~ 5 nm was formed at the boundary between YSZ and silicon. Such an intermediate layer should be formed after the initial formation of the grown YSZ layer as the epitaxy of YSZ still remain. The epitaxy can be kept through all layers without the formation of big grain boundaries. No amorphous layers and secondary phases were observed at the interfaces of YSZ/ECO and YBCO/ECO. The results demonstrate that the crystallinity and the epitaxy of YBCO have been greatly improved by the bi-layer buffer.