Preparation of MgO films on metal substrate as a buffer layer for liquid phase epitaxy processed RE123 coated conductor

Abstract

The fabrication process of in-plane aligned MgO films on metal substrate as a buffer layer for liquid phase epitaxy (LPE) processed RE123 (RE123: RE=Y, Sm, Nd…) coated conductor was developed using the inclined substrate deposition (ISD) method with electron-beam evaporation. The texture development was investigated and a growth mechanism of in-plane alignment was discussed. Although the in-plane alignment of MgO can be obtained due to ISD, the reaction between metal substrate and high temperature melt cannot be prevented by the layer because of the presence of column spacings. Then, a two-step deposition process was developed for LPE method. The first layer was deposited by the ISD to obtain the in-plane alignment and the second layer was deposited at high temperature to realize the full coverage which is necessary to prevent the reaction between metal substrate and MgO-saturated Ba–Cu–O melt. This two-step deposited MgO buffer layers realize both the in-plane alignment and prevention of the reaction, and make the LPE process enable to apply for coated conductors.