%0 Journal Article %T Relaxation path of metastable nanoclusters in oxide dispersion strengthened materials %+ Service des Recherches Métallurgiques Appliquées (SRMA) %+ CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)) %+ Unité Matériaux et Transformations - UMR 8207 (UMET) %A Ribis, J. %A Thual, M.A. %A Guilbert, T. %A de Carlan, Y. %A Legris, A. %< avec comité de lecture %@ 0022-3115 %J Journal of Nuclear Materials %I Elsevier %V 484 %P 183-192 %8 2017-02 %D 2017 %R 10.1016/j.jnucmat.2016.12.007 %K Nanoclusters %K Nano-oxides %K Non-equilibrium %K Relaxation path %K TEM %Z Physics [physics]/Nuclear Theory [nucl-th] %Z Physics [physics]/Nuclear Experiment [nucl-ex]Journal articles %X ODS steels are a promising class of structural materials for sodium cooled fast reactor application. The ultra-high density of the strengthening nanoclusters dispersed within the ferritic matrix is responsible of the excellent creep properties of the alloy. Fine characterization of the nanoclusters has been conducted on a Fe-14Cr-0.3Ti-0.3Y2O3 ODS material using High Resolution and Energy Filtered Transmission Electron Microscopy. The nanoclusters exhibit a cubic symmetry possibly identified as f.c.c and display a non-equilibrium YTiCrO chemical composition thought to be stabilized by a vacancy supersaturation. These nanoclusters undergo relaxation towards the Y2Ti2O7-like state as they grow. A Cr shell is observed around the relaxed nano-oxides, this size-dependent shell may form after the release of Cr by the particles. The relaxation energy barrier appears to be higher for the smaller particles probably owing to a volume/surface ratio effect in reason to the full coherency of the nanoclusters %G English %L cea-02381277 %U https://cea.hal.science/cea-02381277 %~ CEA %~ CNRS %~ ENSC-LILLE %~ INRA %~ DEN %~ INC-CNRS %~ CEA-UPSAY %~ UNIV-PARIS-SACLAY %~ AGREENIUM %~ CEA-UPSAY-SACLAY %~ UNIV-LILLE %~ DEN-SACLAY %~ INRAE %~ TEST-HALCNRS %~ GS-ENGINEERING %~ GS-PHYSIQUE %~ TEST2-HALCNRS