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SrVO3 (SVO) is a model system for strongly correlated oxides and is highly promising as conductive layer in heterostructures. Therefore, the control of electronic properties and morphology are essential for the advanced applications. Here, the oxygen stability during and after the deposition is explored, as SVO film is expected to undergo different postdeposition thermal and atmosphere treatments during its integration in a heterostructure. Hence, the influence of oxygen stability on morphology and electrical properties of the metallic SrVO3 grown by pulsed laser deposition has been investigated. Films grown under vacuum (SrVO3− δ ) exhibit a very smooth surface while films grown under higher oxygen pressure roughen and present nanostructures at the surface. These nanostructures are found to be of Sr3V2O8 phase and their apparition can be controlled by the oxygen supply. Subsequent thermal treatments at different temperatures under same oxygen pressure prevent formation of the Sr3V2O8 phase, lead to the stoichiometric SrVO3, and thus improve the transport properties. In this study is shown the extreme sensitivity of SVO to oxygen and the conditions to obtain high quality smooth SVO films with improved electrical properties for electrode application. [ABSTRACT FROM AUTHOR]

In situ optical characterizations of metal-insulator (MI) transition have been developed in a pulsed laser deposition (PLD) chamber. It consists of associating a spectroscopic ellipsometer and an infrared camera. The first one is sensitive to modifications of the optical indexes and the second one to the emissivity changes. We focus onto the metallic LaNiO3 and the insulating SrTiO3, which present opposite electrical properties as a function of their oxygen content. Using a combinatorial synthesis approach during fabrication by PLD onto LaAlO3 substrate, we observe the evolution of the apparent temperature for different area corresponding to single LaNiO3 or SrTiO3 layers and heterostructures during reduction and reoxygenation process at constant temperature. Thus, the possibility to grow off-stochiometric samples by PLD or to reduce them by heating under high vacuum, associated to the ability of injecting controlled quantity of oxygen by pulsed valve, provide us an original tool in order to study the (MI) transition. [ABSTRACT FROM AUTHOR]

Abstract: Pulsed Laser Deposition of magnetically ordered polycrystalline SmFeO3 films has been optimized onto SiO2 glass substrates as function of substrate temperature, oxygen pressure and pulsed laser fluency. Using a KrF excimer laser, crystallization temperature is found to be about 1048K for a weak fluency of only 1.7Jcm−2. We show that this growth temperature can be reduced using higher fluency and that it is possible to obtain a film texturation along the c axis by reducing the oxygen pressure at given temperature and fluency. In a second part, we focus on the SmFeO3 optical constants determined by in situ ellipsometry using a stacking model and the Cauchy dispersion relation for SmFeO3 layer. We show a good correlation between the transmission and reflection calculated from these data and measured by ex situ spectrophotometry in the visible range. [Copyright &y& Elsevier]

[Display omitted] • SrVO 3 growth by pulsed laser deposition. • Combinatorial Substrate Epitaxy as a powerful tool to obtain a Nanostructures library. • Fast study of nanostructures morphology by AFM versus substrate orientations. • Optical anti-reflective or surface nano-struture wettability applications. SrVO 3 (SVO) is a complex oxide with interesting optical and conduction properties as an indium-free transparent conducting oxide for electrode applications. In this paper, we report how the surface of SVO can be designed at the nanoscale from self-organized Sr 3 V 2 O 8 nanostructures (NS) with different shapes and morphologies depending on crystalline orientations. By combining transmission electron microscopy (TEM) and atomic force microscopy (AFM), we compare the characteristics of the NS for SVO films grown on SrTiO 3 (STO) polycrystalline substrates, according to combinatorial substrate epitaxy (CSE), with those of NS observed from SVO films deposited on STO single crystalline substrates with different crystallographic orientations ((1 0 0), (1 1 0), (1 1 1)). We are able not only to show that the obtained morphologies are correlated to the specific substrate orientation due to the epitaxial relationships between the NS, the SVO, and the substrate, but also to establish a NS library and determine the necessary crystalline orientations for a certain NS morphology on demand. Finally, dissolution of the NS in water leads to typical inverse imprints on the surface of the film, offering a fast and easy way to pattern the electrodes. This work presents a new way of patterning surfaces with a specific design of self-organized NS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sr-rich phases onto SrVO 3 thin films are studied using Angle Resolved XPS. • A treatment in water removes Sr excess by giving a V-OH terminated surface. • A study of air-ageing onto "as-grown" and "H 2 O-treated" SVO is finally pursued. In this work, 40 nm-thick films of SrVO 3 (SVO) grown by Pulsed Laser Deposition (PLD) on SrTiO 3 substrates are studied by X-Ray Photoelectron Spectroscopy (XPS). We develop here a systematic fitting procedure for both Sr3d, V2p 3/2 and O1s spectral regions of interest associated to the different chemical environments. Joint angle resolved XPS and Ar ion depth profiling reveal that as-grown SVO thin films exhibits Sr-rich phases at the extreme surface and a near-stoichiometric SVO in the bulk. The removal of segregated Sr is proposed by a treatment in deionized ultrapure water. This step will become an essential technological step in order to obtain reproducible surfaces achieving a stoichiometric SVO oxide phase. Besides, these hydrolyzed SVO surfaces appears VO 2 terminated and then more electrically active. Furthermore, an air-ageing comparative study between as-grown and H 2 O-treated samples reveals that hydrolyzed surfaces are more surface sensitive to air oxidation. Such observations will be crucial and must be carefully considered before performing any passivation process for the integration of SVO thin film into next generation electronics heterostructures. [ABSTRACT FROM AUTHOR]