Real‐Time Observation of Thermal Surface Recovery in SrVO 3

ABSTRACT Correlated oxides are emerging materials with a broad range of applications in next‐generation devices, most recently as attractive, earth‐abundant transparent conductive electrodes for photovoltaics and electro‐optic devices. SrVO 3 (SVO), a model correlated metal and a promising transparent conducting oxide, develops a several‐nanometer‐thick V 5 + near‐surface region (NSR) under ambient conditions. This oxidized layer obscures the intrinsic correlated‐metallic V 4 + character and limits both fundamental studies of the physics and the material's integration into electronic devices. Here, we demonstrate a direct and controllable approach for recovering the metallic SVO by thermally reducing the NSR under ultra‐high vacuum. Real‐time in situ X‐ray photoelectron spectroscopy reveals a sharp transformation from a V 5 + ‐dominated surface to mixed valence states, dominated by V 4 + (∼65% of the spectral weight), and a recovery of its metallic character. This is compared with a comprehensive ex situ analysis, suggesting this transformation is accompanied by mass redistribution and partial oxygen loss, leading to nanoscale surface reorganization and modest lattice expansion without loss of perovskite crystallographic integrity. These findings establish a practical method for obtaining predominantly V 4 + SVO surfaces without protective capping layers, a capability that expands the engineering and design space of correlated oxides for functional devices.