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.