Photoemission and dynamical mean field theory study of electronic correlations in a t2g5 metal SrRhO3 thin film

Abstract

Perovskite rhodates are characterized by intermediate strengths of both electronic correlation as well as spinorbit coupling (SOC) and usually behave as moderately correlated metals. A recent publication [Phys. Rev. B 95, 245121 (2017)] on epitaxial SrRhO3 thin films reported a bad-metallic behavior and suggested the occurrence of antiferromagnetism below 100 K. We have further studied this SrRhO3 thin film by hard x-ray photoemission spectroscopy and found a very small density of states (DOS) at the Fermi level (EF), which is consistent with the previously reported bad-metallic behavior. However, the absence of DOS persists up to room temperature, which contradicts the explanation of antiferromagnetic transition at ∼100 K. We also employed electronic structure calculations within the framework of density functional theory and dynamical mean-field theory. In contrast to the photoemission results, our calculations indicate metallic behaviors of both bulk SrRhO3 and the SrRhO3 thin f ilm, and a stronger correlation effect was observed in the thin film than that in the bulk. The calculated uniform magnetic susceptibility is substantially larger in the thin film than that in the bulk. We also investigated the role of SOCandfound only a moderate modulation of the band structure. Hence SOC is not expected to significantly affect the electronic correlation in SrRhO3. Extrinsic effects of finite-thickness effects beyond our calculations and localization effects may play important roles to induce the negligible spectral weight at EF.