CHARACTERIZATION OF ULTRAFINE SNO2 POWDERS SYNTHESIZED BY THERMAL PLASMA PROCESS

Ultrafine tin dioxide (SnO2) powders were prepared in a D.C. transferred are plasma furnace. Solid products are formed by condensation of material from the vapor phase in a quenching device. The ultrafine products are collected in a bagfilter. Powders characterization was carried out using X-ray diffraction analysis (XRD), specific surface area measurements (BET method) and Transmission Electron Microscopy (TEM). The morphological characteristics of the powders annealed at high temperatures were remarkably different from those annealed at low temperatures. The grain growth kinetic was studied. Time exponents and activation energies calculated from isothermal annealing data are used to identify the mass transport mechanism involved in the growth process.