Phase composition and stability of Gd2−x Th x Zr2O7 under extreme conditions-Reference-Cited by-同舟云学术

Phase composition and stability of Gd_2−xTh_xZr₂O₇ under extreme conditions

Published:2024-06-01 Issue:5-6 Volume:239 Page:199-205
ISSN:2194-4946
Container-title:Zeitschrift für Kristallographie - Crystalline Materials
language:en
Short-container-title:

Author:

Svitlyk Volodymyr¹²,Weiss Stephan¹,Garbarino Gaston³,Hübner René⁴,Worbs Andreas⁴,Huittinen Nina¹⁵,Hennig Christoph¹²

Affiliation:

1. Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology , 01328 Dresden , Germany

2. 55553 Rossendorf Beamline (BM20), European Synchrotron Radiation Facility , 38000 Grenoble , France

3. 55553 ID15b High Pressure Beamline, European Synchrotron Radiation Facility , 38000 Grenoble , France

4. Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research , 01328 Dresden , Germany

5. Institute of Chemistry and Biochemistry, Freie Universität Berlin , 14195 Berlin , Germany

Abstract

Abstract Introduction of Th into synthetic disordered fluorite-type Gd2Zr2O7 induces a transition to an ordered pyrochlore-type phase at a Th concentration of 10 % at the Gd site (Gd1.8Th0.2Zr2O7 composition). The degree of order of the fluorite-type phase reaches 50 % for a Th concentration of 25 % (Gd1.5Th0.5Zr2O7 composition). Upon application of high pressure, the Gd2Zr2O7 phase retains the fluorite-type structure until 33 GPa (K 0 = 167(1) GPa), where it undergoes reversible amorphization. The Gd1.7Th0.3Zr2O7 phase was found to be stable up to at least a pressure of 25 GPa (K 0 = 169(3) GPa). Upon heating to T max of 1135 K, the Gd2Zr2O7 phase retains its disordered fluorite-type structural arrangement (α = 3.03 × 10−5 K−1). The excellent stability of the Gd2−x Th x Zr2O7 phases under extreme conditions of temperature and pressure makes Gd2Zr2O7 a promising candidate as a host matrix for radioactive elements for safe long-term underground storage of nuclear waste.

Publisher

Walter de Gruyter GmbH

Link

https://www.degruyter.com/document/doi/10.1515/zkri-2024-0066/pdf

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