Heteroepitaxial Growth of Strontium Titanate on Lanthanum Aluminate Using the Metallo-Organic Decomposition Technique.

Abstract

ABSTRACTWe demonstrate the heteroepitaxial growth of thin films of SrTiO3 prepared by the method of Metallo-organic decomposition on LaAlO3 substrates. The SrTiO3 films are prepared by spin coating and thermal decomposition of a solution of Metallo-organic precursors on single-crystal, <100> oriented, LaAK>3 substrates. Subsequent heat treatment at 1100 – 1200 °C for 1 h results in the epitaxial alignment of the SrTiO3 films with respect to the LaAlO3 substrate.The degree of alignment of the films appears to depend on their thickness, with thinner films showing better alignment (as determined by ion-channeling measurements). This behavior is interpreted as a result of the competition between solid-phase epitaxy and random nucleation, observed during the crystallization of films prepared by Metallo-organic decomposition. However, since thinner films have been prepared by dilution of the precursor solution, there is also the possibility that the concentration of the precursor solution may influence the crystallization behavior of the films.The potential influence of the precursor formulation on the crystallization mechanism is discussed.