Epitaxial growth of complex oxide films: Role of surface reconstructions

Abstract

Achieving atomically flat and stoichiometric films of complex multicomponent oxides is crucial to integrating these materials in both established and emerging technologies. While pulsed laser deposition (PLD) can in principle produce these high-quality films, growth experiments often result in unsatisfactory morphologies with rough surfaces and nonstoichiometric compositions. To understand the cause, the growth needs to be followed at an atomic level from its early stages as a function of the growth conditions. By combining PLD with atomically resolved scanning tunneling microscopy, as well as surface spectroscopic and diffraction techniques, we address the origin of surface roughening in SrTiO3(110) homoepitaxial films and pinpoint optimal growth conditions. We highlight the importance of surface reconstructions at all stages of growth: The different sticking on coexisting surface structures is responsible for the roughening of SrTiO3(110) films and affects their stoichiometry.