Crystallite growth kinetics of highly pure nanocrystalline tin dioxide: The effect of palladium doping

TXRD study together with BET, HRTEM and TEM techniques were performed to investigate the effect of Pd doping on crystallite growth kinetics of highly pure nanocrystalline SnO2 during isothermal annealing at 873, 973 and 1073 K. Apparent activation energy for crystallite growth of blank as well as surface and bulk doped SnO2 was estimated applying grain growth model with size-dependent impediment. Low activation energy for blank material (∼23 kJ mol−1) suggests that Sn self-diffusion on the reduced crystallite's surface is the most probable mechanism contributing to the growth process. Together with very low crystallite growth rate blank material demonstrates the highest agglomeration degree after annealing. Doping with Pd does not result in drag effect on crystallite boundary mobility. In contrary, it results in remarkable increase of crystallite growth rate together with an increase in the activation energy. In the case of bulk doped SnO2 the phenomenon of crystallite coalescence was observed.