alpha-Na3M2(PO4)(3) (M = Ti, Fe) : Absolute Cationic Ordering in NASICON-Type Phases

Houria Kabbour (1) , Daniel Coillot (1) , Marie Colmont (1) , Christian Masquelier (2, 3) , Olivier Mentré (1)

1 UCCS - Unité de Catalyse et Chimie du Solide - UMR 8181
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 LRCS - Laboratoire réactivité et chimie des solides - UMR CNRS 7314

The structure of the fully ordered R-Na3Ti2(PO4)3 NASICON compound was elucidated using highquality single-crystal data. The cation/vacancy distribution forms a homogeneous 3D arrangement and could represent the absolute cationic ordering available in the full Na3M2(PO4)3 series, as verified for M = Fe. For M = Ti, the reversible Rfγ transition was observed at 85 C, leading to the standard disordered R3c γ model. Through JPDF analysis, the most probable Na+ zigzag M(2) M(1) diffusion scheme was directly deduced using our accurate crystallographic data.

Domaines: Cristallographie; Matériaux

Houria Kabbour, Daniel Coillot, Marie Colmont, Christian Masquelier, Olivier Mentré. alpha-Na3M2(PO4)(3) (M = Ti, Fe) : Absolute Cationic Ordering in NASICON-Type Phases. Journal of the American Chemical Society, 2011, 133, pp.11900-11903. ⟨10.1021/ja204321y⟩. ⟨hal-00822469⟩