2D Surface Phase Diagram of a Multicomponent Perovskite Oxide: La${}_{0.8}$Sr${}_{0.2}$MnO${}_3$(110)

Abstract

The many surface reconstructions of (110)-oriented lanthanum--strontium manganite (La${}_{0.8}$Sr${}_{0.2}$MnO${}_3$, LSMO) were followed as a function of the oxygen chemical potential (${\mu }_{\text{O}}$) and the surface cation composition. Decreasing ${\mu }_{\text{O}}$ causes Mn to migrate across the surface, enforcing phase separation into A-site-rich areas and a variety of composition-related, structurally diverse B-site-rich reconstructions. The composition of these phase-separated structures was quantified with scanning tunneling microscopy (STM), and these results were used to build a 2D phase diagram of the LSMO(110) equilibrium surface structures.