Constant Rate Thermal Analysis (CRTA) as a Tool for the Synthesis of Materials with Controlled Texture and Structure

Abstract

Some examples of the use of the CRTA method for the synthesis of materials with controlled texture and structure are given. BaTiO 3 has been obtained from the thermal decomposition of Barium Titanyl Oxalate (BTO) and Barium Titanyl Citrate (BTC) by controlling the reaction temperature in such a way that the partial pressure of the gases generated in the reaction was maintained constant at a value close to 10 -2 mbar. It has been shown that this method allows getting BaTiO 3 with crystal sizes considerably lower than those obtained by decomposing the same precursors by conventional methods. This small crystal sizes lead to the stabilisation of the metastable cubic phase with regards to the tetragonal phase. It has been also shown that the control of the CO generated in the carbothermal reduction of silica allows tailoring the phase composition of the silicon nitride obtained as final product.