Coherent growth of oxide films on a cleaved layered metal oxide substrate

Understanding oxide interface-induced effects requires controlled epitaxial growth of films on well-defined substrate surfaces. While conventional film growth on ex situ prepared substrates has proven to be a successful route, the choices of appropriate substrates with atomically defined surfaces are limited. Here, by depositing La2/3Sr1/3MnO3 on Sr2RuO4 (001), we present an alternative method of growing oxide thin films on in situ cleaved surfaces of layered-structured substrates. Cleaving Sr2RuO4 at low temperature in ultrahigh vacuum exposes an atomically flat, solely SrO-terminated surface with up to micrometer-scale terraces. The deposition of La2/3Sr1/3MnO3 spontaneously diminishes the surface RuO6 in-plane rotational distortion of the substrate and results in a cubic-like perovskite film structure with (La/Sr)-O layer termination. The interface is atomically sharp without obvious deviation of lattice spacing and chemical valence, except in the first unit cell where Ru-Mn intermixing is observed. These results demonstrate that film growth on a cleaved substrate can be an alternative route to obtain well-defined interfaces and in addition increase the availability of substrates for future oxide films.