Molecular Dynamics Simulation of Sintering Dynamics of Many TiO₂ Nanoparticles

The sintering processes of many TiO₂ nanoparticles in chains of both solid and liquid phases have been studied in detail via molecular dynamics simulation. For the liquid phase, a modified correlation for the characteristic sintering time of multi-particle chains is obtained by including a correction factor of ^(N/2)1/3, where N is the number of primary particles. The temperature rise during sintering is found to be linearly proportional to(1-^N-1/3). Moreover, this study provides a way to calculate the surface energy of nanoparticles of small diameters in liquid phase, which is experimentally unattainable. For the solid phase, sintering induced nucleation is observed for N≥4 cases both at T₀= 1220 and 960 K with a sharp increase in the temperature and a decrease in the potential energy. The formation of rutile from nucleation of many solid amorphous particles through sintering is observed for the first time.