Surface Characterizations and Selective Etching of Sr‐Rich Segregation on Top of SrVO₃ Thin‐Films Grown by Pulsed Laser Deposition

Abstract Since SrVO₃ (SVO) can be used as a highly conductive material for perovskite heterostructures, the control of surface morphology and chemistry of such thin‐films are essential. Using pulsed laser deposition, two distinct topographies can be produced. Thus, by tuning oxygen pressure in the growth chamber during cooling, smooth or partially covered by self‐oriented Sr₃V₂O₈ nanorods surfaces can be grown. This study manages to correlate the two typical topographies, revealed by atomic force microscopy (AFM), with their chemical compositions obtained by X‐ray photoelectron spectroscopy (XPS). At first, a model describes their initial surface chemistry through the Sr/V cationic ratio and the (Sr+V)/O_ox ratio. Furthermore, using sputter‐depth profiling, post‐thermal treatments and wet chemical etching, SVO thin‐film chemical compositions are extensively studied. We demonstrate that they are composed of stoichiometric SVO phase covered by Sr‐rich layer on top. Finally, treatment in water for 180 seconds helps to remove Sr‐rich phases. Sr₃V₂O₈ nanorods are found selectively dissolved leaving a surface nano‐imprint. Moreover, on smooth SVO surfaces, a balanced Sr/V cationic ratio of 1.0±0.1 is obtained. These results appear very promising for SVO thin‐films surface preparation and further development as electrodes for electronic devices.