Kinetic study of a way of solid state synthesis of barium titanate
Résumé
The aim of this work is to study a way of solid state synthesis of barium titanate, from barium nitrate and titanium dioxide. The reaction path has first been identified, i.e. the intermediate phases that can appear during the reaction, from a thermodynamical and experimental point of view. Experimental conditions of temperature and partial pressures of nitrogen monoxide and oxygen (which are the main gases released during the reaction) have been chosen such as BaTiO3 is the stable phase. The experimental kinetic curves have been obtained using thermogravimetry, in isothermal conditions, under controlled partial pressures of nitrogen monoxide and oxygen. These gases have an inhibiting effect on the reaction. A qualitative interpretation of the transformation is proposed, as well as a geometrical modeling that leads to the variations of the fractional conversion with time.