Structural Analysis of Sol-Gel-Derived LaNiO3(100)/CeO2(100)/Si(100) Heterostructures.

Abstract

LaNiO3(100)/CeO2(100)/Si(100) as a metal/insulator/semiconductor heterostructure was prepared by a sol-gel method with a spin-coating technique. The structure of each oxide layer was investigated by out-of-plane and in-plane X-ray diffraction analyses. The high degree of {100} -orientation of the CeO2 layers was obtained with higher heat treatment temperatures, 600-700°C. The in-plane measurements revealed that the CeO2 layers had a nonepitaxial structure in spite of the deposition on the Si(100) substrates with good lattice compatibility. The LaNiO3 layers on the CeO2(100)/Si(100) also exhibited the preferential {100} -orientation without epitaxy. The crystallinity of the {100} -oriented grains in the LaNiO3 layers was higher than that in the CeO2 layers. The occurrence of the orientation was discussed in view of the interfacial energies at each interface.