KINETIC-STUDY OF A WAY OF SOLID-STATE SYNTHESIS OF BARIUM-TITANATE

The aim of this work is to study a way of solid state synthesis of bar ium titanate, from barium nitrate and titanium dioxide. The reaction p ath has first been identified, i.e. the intermediate phases that can a ppear during the reaction, from a thermodynamical and experimental poi nt of view. Experimental conditions of temperature and partial pressur es of nitrogen monoxide and oxygen (which are the main gases released during the reaction) have been chosen such as BaTiO3 is the stable pha se. The experimental kinetic curves have been obtained using thermogra vimetry, 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 i s proposed, as well as a geometrical modeling that leads to the variat ions of the fractional conversion with time.