Seed layers on RABiTS tapes for Second-Generation HTS wires

Epitaxial films of CeO$_2$ and Y$_2$O$_3$ on RABiTS metal tapes have been obtained by pulsed laser deposition. The dependence of the film crystal orientation on the temperature of synthesis has been studied. It is established that Y$_2$O$_3$ films grow with 100% (100) orientation, whereas a parasitic orientation is present in CeO$_2$ films obtained in the entire range of growth temperatures. The texture sharpness in the substrate plane amounted to 8$^\circ$. Electron-microscopic examination showed that an increase in the temperature of synthesis leads to the appearance of cracks on the surface of CeO$_2$ films, while the surface of Y$_2$O$_3$ films remains continuous in the entire range of growth temperatures. Thus, Y$_2$O$_3$ films most fully obey the requirements to seed layers in (i) being epitaxial with 100% (100) crystal orientation, (ii) inheriting the substrate texture, and (iii) having a smooth crack-free surface.