GROWTH MECHANISMS OF EPITAXIAL METALLIC OXIDE SRRUO3 THIN-FILMS STUDIED BY SCANNING-TUNNELING-MICROSCOPY

We report the deliberately controlled growth of epitaxial metallic oxi de SrRuO3 thin films in three distinctly different growth modes. Scann ing tunneling microscopy and x-ray diffraction indicate that the growt h mechanism for films on exact (001) SrTiO3 substrates is two-dimensio nal nucleation, which results in a two domain in-plane structure. As t he miscut angle of vicinal (001) SrTiO3 substrates is increased, the g rowth mechanism changes to step flow which leads to single domain thin films. Films on (001) LaAlO3 substrates have an incoherent three-dime nsional island growth due to the large lattice mismatch, resulting in a bulk-like lattice. The vast difference in the growth mechanisms of t hese films leads to a corresponding difference in their electrical tra nsport and magnetic behavior. Such nanoscale control of growth mechani sm, surface morphology, and domain structure can be very important in the fabrication of novel perovskite oxide devices. (C) 1997 American I nstitute of Physics.