X-ray scattering and EXAFS studies of Pt1−xVx alloys

Alain Gibaud (1) , M. Topić (2) , Gwenaël Corbel (3) , V. Briois (4) , D. Thiaudiere (4) , A. Pineda-Vargas (2) , T. Ntsoane (5)

1 LPEC - Laboratoire de physique de l'état condensé
2 iThemba LABS [National Research Foundation]
3 LdOF - Laboratoire des oxydes et fluorures
4 SSOLEIL - Synchrotron SOLEIL
5 Necsa

Alloys of the Pt–V system between 0 and 50 at.% V have been investigated by X-ray scattering and extended X-ray absorption fine structure (EXAFS). The variation of lattice parameter with the nominal chemical composition was measured and compared to previously reported values. The solid solution was observed in alloys containing up to 20 at.% V. In the alloy with higher vanadium concentration, 50 at.% V, we found that the alloy is not homogeneous and exhibits a segregation of Pt and PtV phases in addition to VO2(M) phase. These experiments are complemented by EXAFS measurements made at the K edge of V which clearly show the sensitivity of this technique to V content. Determination of the local environment of V and Pt is made via a basic model taking in account the first neighbours only. A discussion is presented about the comparison between X-ray and EXAFS results obtained from the same samples.

Mots clés: Metals and alloys; Composition fluctuation; X-ray diffraction; EXAFS

Domaines: Cristallographie; Chimie inorganique; Matériaux

Alain Gibaud, M. Topić, Gwenaël Corbel, V. Briois, D. Thiaudiere, et al.. X-ray scattering and EXAFS studies of Pt1−xVx alloys. Journal of Alloys and Compounds, 2013, 562, pp.95-98. ⟨10.1016/j.jallcom.2013.01.059⟩. ⟨hal-02138603⟩