Surface Characterizations and Selective Etching of Sr‐Rich Segregation on Top of SrVO3 Thin‐Films Grown by Pulsed Laser Deposition. Issue 5 (5th March 2019)

• Record Type: Journal Article
• Authors: Bourlier, Yoan; Frégnaux, Mathieu; Bérini, Bruno; Fouchet, Arnaud; Dumont, Yves; Aureau, Damien
• Is Part Of: ChemNanoMat. Volume 5:Issue 5(2019)
• Page Start: 674
• Page End: 681
• Publication Date: 2019-03-05
• Subjects: SrVO3 -- perovskite oxides -- nanorods -- surface reactions -- thin films; Nanochemistry -- Periodicals; Nanostructured materials -- Periodicals; Nanochemistry; Nanostructured materials; Periodicals; 541.2
• DOI: 10.1002/cnma.201900017
• Languages: English
• ISSNs: 2199-692X

Abstract

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 Sr3 V2 O8 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)/Oox 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. Sr3 V2 O8 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. Abstract : SrVO3 thin‐films are grown using pulsed layer deposition . Both nanostructured and smooth surfaces are produced. XPS reveals a segregation of Sr‐rich phases that are dissolved in water. AFM shows selective etching of the Sr3 V2 O8 nanostructures. This easy‐to‐use treatment makes the surface of smooth films stoichiometric with Sr/V=1.0. These results appear interesting for further improvements on micro/nano electronic devices.