(100)-orientation of pseudocubic perovskite-type LaNiO₃ thin films on glass substrates via the sol-gel process

(100)-oriented, perovskite-type LaNiO₃ thin films were prepared on SiO₂ glass substrates by the sol-gel method. Effects of thermal processing on the orientation, surface morphology, and electrical properties of the films were investigated. The nearly complete (100)-orientation was achieved by drying the films at temperatures above 350°C before a final heat treatment at 700°C. It was the key to heat the substrate from the other side to obtain the oriented films. A possible mechanism of the orientation is proposed on the basis of surface energies of the films and the substrates and the interracial energy between them.