The Lattice Stiffening Transition in UO₂ Single Crystals

Authors

Christopher Young, United States Air Force Institute of Technology
James Petrosky, United States Air Force Institute of TechnologyFollow
J. Matthew Mann, United States Air Force Research Laboratory
Eric M. Hunt, United States Air Force Research Laboratory
David Turner, United States Air Force Research Laboratory
Peter A. Dowben, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2017

Citation

Journal of Physics: Condens. Matter 92017) 29: 035005

doi: 10.1088/1361-648X/29/3/035005

5 pages

Comments

© 2016, IOP Publishing.

This document is a United States government work and is not subject to copyright in the United States

Abstract

The effective Debye temperatures (θ_DE) of the surface region of UO₂ single crystals, prepared by the hydrothermal synthesis technique, were obtained from temperature-dependent x-ray photoemission in the temperature range of 300 K–623 K. A lattice stiffening transition, characterized by different regions of different effective Debye temperature, 500 ± 59 K below 475 K and 165 ± 21 K above 475 K is identified. A comparison of the temperature dependence of the effective UO₂ Debye temperature, with the changes in the lattice expansion coefficient for UO₂, support strong lattice-phonon interaction arising from the Jahn–Teller distortion.