First study of uranium self-diffusion in UO2 by SIMS.

Abstract

Uranium self-di€usion coe cients were measured in UO2 single crystals through an original methodology based on the utilization of 235U as tracer and depth pro®ling by secondary ion mass spectrometry (SIMS). The values of the selfdi €usion coe cients measured in this work, between 1498 and 1697°C, in H2 atmosphere, can be described by the following Arrhenius relation: D (cm2/s).8.54 ´ 10ÿ7exp[)4.4(eV)/kT], and are lower than those previously determined by other authors in `nearly stochiometric' UO2 in the same temperature range. Ó 1998 Elsevier Science B.V. All rights reserved.