Initial stage in the liquid phase epitaxy of Nd123 films: dependence of growth rate on process parameter

Abstract

Coated conductors are promising candidates for applications. In order to apply the liquid phase epitaxy (LPE) technique to the coated conductor process, some buffer layers are necessary to prevent reaction with the substrate and to provide an appropriate texture for the single crystalline growth of the superconducting films. On NiO buffer layers, Ni saturated Nd123 films grown by LPE are suitable as a second buffer layer for the growth of superconducting Sm123 or Y123 films. The buffer layer should be as thin as possible from the engineering point of view. However, Nd123 has a much higher growth rate in comparison with Y123. This means that it is difficult to control the growth rate of the Nd123 system. Especially, as the growth of Nd123 depends strongly on the process parameters e.g. supersaturation and oxygen partial pressure, we measured the supersaturation during the experiments and determined their influence on the growth rate and the characteristics of the films in order to control the thickness of the second buffer layer.