Structure and properties of cerium oxides in bulk and nanoparticulate forms

    Authors

    S. Gangopadhyay; D. D. Frolov; A. E. Masunov;S. Seal

    Comments

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    Abbreviated Journal Title

    J. Alloy. Compd.

    Keywords

    DFT; Nanoceria; Core-shell structure; Cerium dioxide; Oxygen vacancy; DENSITY-FUNCTIONAL THEORY; GGA PLUS U; TRANSMISSION ELECTRON-MICROSCOPY; COMPACT EFFECTIVE POTENTIALS; INDUCED PHASE-TRANSFORMATION; EXPONENT; BASIS-SETS; F-SYMMETRY STATES; CEO2 THIN-FILMS; OPTICAL-PROPERTIES; SPECTROSCOPIC EVIDENCE; Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy &; Metallurgical Engineering

    Abstract

    The experimental and computational studies on the cerium oxide nanoparticles, as well as stoichiometric phases of bulk ceria are reviewed. Based on structural similarities of these phases in hexagonal aspect, electroneutral and non-polar pentalayers are identified as building blocks of type A sesquioxide structure. The idealized core/shell structure of the ceria nanoparticles is described as dioxide core covered by a single pentalayer of sesquioxide, which explains the exceptional stability of subsurface vacancies in nanoceria. The density functional theory (DFT) predictions of the lattice parameters and elastic moduli for the Ce(IV) and Ce(III) oxides at the hybrid DFT level are also presented. The calculated values for both compounds agree with available experimental data and allow predicting changes in the lattice parameter with decreasing size of the nanoparticles. The lattice parameter is calculated as equilibrium between contraction of sesquioxide structure in the core, and expansion of dioxide structure in the shell of the nanoparticle. This is consistent with available XRD data on ceria NPs obtained in mild aqueous conditions. The core/shell model, however, breaks down when applied to the size dependence of lattice parameter in NPs obtained by the laser ablation techniques. (C) 2013 Elsevier B. V. All rights reserved.

    Journal Title

    Journal of Alloys and Compounds

    Volume

    584

    Publication Date

    1-1-2014

    Document Type

    Review

    Language

    English

    First Page

    199

    Last Page

    208

    WOS Identifier

    WOS:000327135400032

    ISSN

    0925-8388

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