Control of the growth and domain structure of epitaxial SrRuO3 thin films by vicinal (001) SrTiO3 substrates

Abstract

We report the effect of both miscut angle (α) and miscut direction (β) of vicinal substrates on the epitaxial growth and domain structure of isotropic metallic oxide ${\mathrm{SrRuO}}_3$ thin films. The thin films have been grown on vicinal (001) ${\mathrm{SrTiO}}_3$ substrates with α up to 4.1° and β up to 37° away from the in-plane [010] axis. Single-crystal epitaxial (110)^o ${\mathrm{SrRuO}}_3$ thin films were obtained on vicinal ${\mathrm{SrTiO}}_3$ substrates with a large miscut angle (α=1.9°, 2.1°, and 4.1°) and miscut direction close to the [010] axis. Decreasing the substrate miscut angle or aligning the miscut direction close to the [110] axis (β=45°) resulted in an increase of 90° domains in the plane. The films grown on vicinal substrates displayed a significant improvement in crystalline quality and in-plane epitaxial alignment as compared to the films grown on exact (001) ${\mathrm{SrTiO}}_3$ substrates. Atomic force microscopy revealed that the growth mechanism changed from two-dimensional nucleation to step flow growth as the miscut angle increased.