Sodium Ion Mobility in Na_xCoO₂ (0.6 < x < 0.75) Cobaltites Studied by ²³Na MAS NMR

Dany Carlier-Larregaray (1) , Maxime Blangero (1) , Michel Ménétrier (1) , Michaël Pollet (1) , Jean-Pierre Doumerc (1) , Claude Delmas (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Various P2 and P′3-Na_xCoO₂ phases, with x ranging approximately from 0.6 to 0.75, have been studied by variable-temperature ²³Na magic angle spinning (MAS) NMR. Signal modification versus temperature plots clearly show that Na⁺ ions are not totally mobile at room temperature on the NMR time scale. As the temperature increases, the line shape change of the ²³Na MAS NMR signal differs for the P2 and P′3 stackings and is interpreted by the differences of Na⁺ ion sites and of sodium diffusion pathways in the two structures.

Domaines: Matériaux

Dany Carlier-Larregaray, Maxime Blangero, Michel Ménétrier, Michaël Pollet, Jean-Pierre Doumerc, et al.. Sodium Ion Mobility in Na_xCoO₂ (0.6 < x < 0.75) Cobaltites Studied by ²³Na MAS NMR. Inorganic Chemistry, 2009, 48 (15), pp.7018-7025. ⟨10.1021/ic900026c⟩. ⟨hal-00418632⟩