Strong intensity oscillations have been found in reflection high-energy electron diffraction during epitaxial growth of ${\mathrm{BaTiO}}_3$, ${\mathrm{La}}_2$${\mathrm{CuO}}_4$, and ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{7\mathrm{-}\mathit{x}}$ with perovskite-type structures. The oscillation period corresponds to the height of the minimum unit of each oxide that satisfies the chemical composition and electrical neutrality. The data provide a basic understanding of the epitaxial growth process of ionic oxides.

• Received 5 June 1990

DOI:https://doi.org/10.1103/PhysRevLett.65.2684