Ion Beam Radiation Effects in Monazite.

Valérie Picot (1) , Xavier Deschanels (1) , Sylvain Peuget (2) , Benoit Glorieux (3) , Anne-Magali Seydoux-Guillaume (4) , Richard Wirth (5)

1 LNER - Nanomatériaux pour l'Energie et le Recyclage
2 LMPA - Laboratoire des Matériaux et Procédés Actifs
3 IMP-CNRS - Institut De Science Et De Génie Des Matériaux Et Procédés
4 GET - Géosciences Environnement Toulouse
5 GFZ - German Research Centre for Geosciences - Helmholtz-Centre Potsdam

Monazite is a potential matrix for conditioning minor actinides arising from spent fuel reprocessing. The matrix behavior under irradiation must be investigated to ensure long-term containment performance. Monazite compounds were irradiated by gold and helium ions to simulate the consequences of alpha decay. This article describes the effects of such irradiation on the structural and macroscopic properties (density, hardness) of monazites LaPO4 and La0.73Ce0.27PO4. Irradiation by gold ions results in major changes in the material properties. At a damage level of 6.7 dpa, monazite exhibits volume expansion of about 8.1%, a 59% drop in hardness, and structure amorphization, although Raman spectroscopy analysis shows that the phosphate-oxygen bond is unaffected. Conversely, no change in the properties of these compounds was observed after He ion implantation. These results indicate that ballistic effects predominate in the studied dose range.

Domaines: Minéralogie

Valérie Picot, Xavier Deschanels, Sylvain Peuget, Benoit Glorieux, Anne-Magali Seydoux-Guillaume, et al.. Ion Beam Radiation Effects in Monazite.. Journal of Nuclear Materials, 2008, 381 (3), pp.290-296. ⟨10.1016/j.jnucmat.2008.09.001⟩. ⟨hal-00606691⟩