Showing papers by "Alain Levasseur published in 2005"
TL;DR: In this article, the electrochemical properties of several TiOySz thin films prepared by radio frequency magnetron sputtering in a pure argon or mixed oxygen/argon plasma were investigated.
51 citations
TL;DR: Amorphous and crystalline vanadium pentoxide thin films have been deposited by rf magnetron sputtering in a pure argon or mixed argon/oxygen atmosphere using a V2O5 target with no intentional heating of the substrate as mentioned in this paper.
27 citations
TL;DR: In this paper, the influence of the sputtering conditions (target, total pressure, oxygen partial pressure) on the composition, the morphology and the local and electronic structure of the titanium oxysulfide thin films were studied.
19 citations
01 Jan 2005
TL;DR: In this paper, the influence of the sputtering conditions (target, total pressure, oxygen partial pressure) on the composition, the morphology and the local and electronic structure of the titanium oxysulfide thin films were studied.
Abstract: Different titanium oxysulfide thin films were prepared by rf magnetron sputtering using two types of targets in a pure argon or mixed oxygen/argon atmosphere with a total pressure of 1 or 0.2 Pa. We have studied the influence of the sputtering conditions (target, total pressure, oxygen partial pressure) on the composition, the morphology and the local and electronic structure of our thin films. A set of complementary techniques (scanning electron microscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS)) was used to characterize the thin films. Two types of films have been obtained: thin films prepared from TiS2 target having a composition and a local structure close to TiS3 and thin films obtained from TiS2/TiS3 target characterized by a composition and a local structure close to TiS2. The complementary use of XPS and sulfur K-edge XAS spectroscopies has allowed us to evidence the coexistence of different microdomains into the thin films corresponding respectively to a pure sulfur, a pure oxygen or a mixed sulfur/oxygen environment. D 2005 Elsevier B.V. All rights reserved.
14 citations
TL;DR: In this paper, amorphous thin films were prepared by radio frequency magnetron sputtering from a TiS 2 target under pure argon atmosphere and two complementary techniques, X-ray photoelectron spectroscopy (X-ray PES) and x-ray absorption spectroscopic analysis, were used to investigate the local and electronic structure of the as-prepared sample and to study the electrochemical mechanisms occurring during the first cycle.
Abstract: Amorphous thin films were prepared by radio frequency magnetron sputtering from TiS 2 target under pure argon atmosphere. Two complementary techniques, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy, were used to investigate the local and electronic structure of the as-prepared sample and to study the electrochemical mechanisms occurring during the first cycle. The results exhibit that the as-prepared TiO 0 . 6 S 2 . 8 thin film is close to bulk TiS 3 [which may be viewed as Ti 4 + (S 2 - 2 )S 2 - ] with regard to the local and electronic structure. An electrochemical characterization of the film was performed. Upon lithium insertion, sulfur is first involved in the electrochemical reduction, followed by titanium. The reduction of S 2 - 2 to S 2 - is concomitant with the elongation of the distance between the two sulfur ions of the disulfide pair. At the end of the charge, the electrochemical processes appear to be reversible. This study clearly evidences the major contribution of sulfur atoms beside titanium.
13 citations