Open AccessEffect of non-stoichiometry on optical, radiative, and thermal characteristics of ceria undergoing reduction
Author(s) -
Vincent M. Wheeler,
José Zapata,
Peter B. Kreider,
Wojciech Lipiński
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.00a360
Subject(s) - refractive index , materials science , ellipsometry , stoichiometry , absorption (acoustics) , chemical composition , radiative transfer , optics , attenuation coefficient , thermal radiation , analytical chemistry (journal) , molar absorptivity , thermal , thin film , thermodynamics , optoelectronics , chemistry , composite material , nanotechnology , physics , chromatography
The complex refractive index of ceria has been determined at ambient temperature using variable angle spectroscopic ellipsometry for two chemical states-fully oxidized and partially reduced. The ellipsometric model is corroborated with complementary measurements of thickness, surface roughness, and chemical composition. Partially reduced ceria is shown to have a larger absorption index over a broad spectral range than fully oxidized ceria, including the visible and near IR regions. We use a simple model of a directly irradiated particle entrained in a gas flow to demonstrate the consequences of accounting for changes in chemical state when modeling ceria-based thermochemical process.