Synthesis and characterization of sodium titanates Na₂Ti₃O₇ and Na₂Ti₆O₁₃

Anne-Laure Sauvet (1) , Sébastien Baliteau (1) , Christian Lopez (1) , Pierre Fabry (1)

1 LEPMI - Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces

Na₂Ti₃O₇ and Na₂Ti₆O₁₃ were synthesized by sol–gel method in order to obtain pure phases. Different heat-treatments were applied on powders and pellets of these materials. The effects were studied by XRD, dilatometry, TGA-DTA, SEM and electrochemical impedance spectroscopy. Pure Na₂Ti₃O₇ was obtained at 973 K. Sintering at 1373 K caused a partial decomposition into Na₂Ti₆O₁₃. The Na₂Ti₃O₇ powder sintered at 1273 K showed polygonal microstructure. Na₂Ti₃O₇ pellets sintered at 1323 K for 10 h exhibited large structures. This latter microstructure decreased the electrical conductivity of Na₂Ti₃O₇. Pure Na₂Ti₆O₁₃ was obtained at 873 K. Sintering at 1073 K caused a partial decomposition into TiO₂ (rutile). Na₂Ti₆O₁₃ pellets sintered at 1323 K for 10 h exhibited common shrinkage behavior. This shrinkage process increased the electrical conductivity of this material. The presence of TiO₂ resulted in a oxygen partial pressure dependence of the electrical conductivity.

Mots clés: Sodium titanates; Structural characterization; EIS; Conductivity

Domaines: Matériaux

Anne-Laure Sauvet, Sébastien Baliteau, Christian Lopez, Pierre Fabry. Synthesis and characterization of sodium titanates Na₂Ti₃O₇ and Na₂Ti₆O₁₃. Journal of Solid State Chemistry, 2004, 177 (12), pp. 4508-4515. ⟨10.1016/j.jssc.2004.09.008⟩. ⟨hal-00417913⟩