Grain Growth kinetics of MnM_2 or CoO doped snO_2

摘要

A study of grain growth kinetics can give information about the mass transport mechanism. CoO or MnO_2 doped SnO_2 powders were prepared by ball mill mixing followed by isostatic pressing and sintering in the temperature range from 1210 to 140CTC. In both systems an exponential reduction of the grain growth rate and increase in the kinetic grain growth coefficient (n) with temperature were observed. The results in both systems suggest that the main mechanism responsible for grain growth is grain boundary diffusion. This assumption is related to the fact that grain growth reduces the specific grain boundary area with a consequent decrease of the mass diffusion.