Solid-Solid Reaction, I: Experimental Study of Barium Metatitane Synthesis

International audienceThe solid-state reaction between barium carbonate and rutile powders to form barium metatitane BaTiO3 was studied by themogravimetric analysis, X rays, and microscopy. Phase-stability domains were drawn in a temperature -Pco2, diagram. The dependence of the reaction kinetics on Pco2, Po2 or Pn2 is discussed. In particular, the rate continuously decreases when Pco2 or Pn2 increases, but it reaches a maximum as a function of Po2. For given partial pressures of gases and temperature the kinetics curves (conversion degree vs.time) may be interpreted by a "hampered" -diffusion mechanism