Electron Magnetic Resonance Investigation of Gadolinium Diffusion in Ceria Powders

Abstract

The electron magnetic resonance (EMR) technique was used to investigate the diffusion of gadolinium in ceria (CeO2) powders. The EMR absorption intensity was measured for several annealing times and three different temperatures of isothermal annealing: 1273, 1323, and 1373 K. The activation temperature for diffusion, calculated from the experimental data using a theoretical model based on the Fick equation, was found to be EA=485±5 kJ/mol. This value is very close to the one obtained for the diffusion of gadolinium in an oxide with a similar crystal structure, UO2, using the secondary ion mass spectrometry technique, EA=492 kJ/mol. On the other hand, it is much larger than the one obtained for the diffusion of gadolinium in yttrium vanadate (YVO4), EA=177 kJ/mol, a compound with a different crystal structure.