Electronic properties of epitaxial cerium oxide films during controlled reduction and oxidation studied by resonant inelastic X-ray scattering. Issue 30 (13th July 2016)

• Record Type: Journal Article
• Authors: Gasperi, Gabriele; Amidani, Lucia; Benedetti, Francesco; Boscherini, Federico; Glatzel, Pieter; Valeri, Sergio; Luches, Paola
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 30(2016)
• Page Start: 20511
• Page End: 20517
• Publication Date: 2016-07-13
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp04407g
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We investigated the evolution of the electronic structure of cerium oxide ultrathin epitaxial films during reduction and oxidation processes using resonant inelastic X-ray scattering at the Ce L3 absorption edge. Abstract : We investigated the evolution of the electronic structure of cerium oxide ultrathin epitaxial films during reduction and oxidation processes using resonant inelastic X-ray scattering at the Ce L3 absorption edge, a technique sensitive to the electronic configurations at the 4f levels and in the 5d band thanks to its high energy resolution. We used thermal treatments in high vacuum and in oxygen partial pressure to induce a controlled and reversible degree of reduction in cerium oxide ultrathin epitaxial films of different thicknesses. Two dominant spectral components contribute to the measured spectra at the different degrees of oxidation/reduction. In ultrathin films a modification of the electronic properties associated with platinum substrate proximity and with dimensionality is identified. The different electronic properties induce a higher reducibility in ultrathin films, ascribed to a decrease of the surface oxygen vacancy formation energy.