The fluorite related modulated structures of the Gd2(Zr2−xCex)O7 solid solution: An analogue for Pu disposition

• Published in: Journal of solid state chemistry 2012-07, Vol.191, p.2-9
• Main Authors: Reid, D.P., Stennett, M.C., Hyatt, N.C.
• Format: Article
• Language: English
• Subjects: Ceramic; Ceramics; Condensed matter: structure, mechanical and thermal properties; Convergent-beam electron diffraction, selected-area electron diffraction, nanodiffraction; Cross-disciplinary physics: materials science; rheology; Electron diffraction; Electron diffraction and scattering; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Fluorite; General studies of phase transitions; Incommensaturate crystals; Materials science; Modulated structure; Nuclear; Order-disorder and statistical mechanics of model systems; Phase diagrams; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase diagrams of metals and alloys; Physics; Plutonium; Pyrochlore; Pyrochlores; Reflection; Semi-periodic solids; Solid solutions; Spectra; Structure of solids and liquids; crystallography
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2011.12.039

We present an overview of the Gd2(Zr2−xCex)O7 phase diagram, of interest as a model system for ceramic disposition of Pu (with Ce as a Pu surrogate). The fluorite related structures of this solid solution were determined using a modulated structure approach, to identify the underlying cation and vacancy ordering mechanisms from analysis of key satellite reflections in selected zone axis electron diffraction patterns. This revealed the formation of four structure types: pyrochlore for x