Heteroepitaxial growth behavior of SrRuO 3/SrTiO 3(001) thin films during early stages by pulsed laser deposition was investigated using synchrotron x-ray scattering, atomic force microscopy, and high-resolution transmission electron microscopy. We find that three-dimensional (3D) SrRuO 3(110) islands of ∼1500 Å in diameter grow at an initial stage of growth (30 Å in thickness), in contrast to the two-dimensional layer growth previously reported in thick (3000 Å) films by off-axis sputtering. Interestingly, the 3D islands are coherently strained to the substrate, possessing a very narrow mosaic distribution of 0.007° half width at half maximum. On top of the existing well-aligned islands, poorly aligned 3D islands of much smaller sizes progressively grow, reducing the interfacial strain while maintaining the small surface roughness of 9 Å up to the film thickness of 420 Å.
ASJC Scopus subject areas
- Physics and Astronomy(all)