Anisotropy of crystallite growth during sintering of SnO2 xerogels
Journal of Materials Science, v. 31, n. 15, p. 4087-4092, 1996.
Brito, G. E S
Pulcinelli, Sandra Helena
Santilli, Celso Valentim
The crytallite and pore-size evolution during isothermal sintering (400 ≤ T ≤ 700°C) of SnO2 xerogels was studied by X-ray line broadening and nitrogen adsorption-desorption isotherms. The experimental results show a strong anisotropy of crystallite growth between  and  directions. The preferential growth at  is followed by an increase in the mean pore size, reduction of the specific surface area and invariance of total pore volume. This behaviour is typical of grain coalescence sintering. The kinetic analysis of experimental results suggests that the crystallite coalescence at  is governed by lattice diffusion. The strong anisotropy of the growth causes pore-size distribution broadening, hindering the macroscopic shrinkage of the compact during sintering. © 1996 Chapman & Hall.