Surface diffusivity under high-pressure gas

The sintering behavior of TiO2 under high-pressure gas (100 MPa) was studied with respect to densification rate, decreasing rate of specific surface area, and narrowing rate of pore size distribution. At the low sintering temperature (800°C) used in this study, the densification rate under high-pressure gas was similar to that under low (i.e., 1 atm) pressure. The specific surface area decreased and the pore size distribution narrowed at a faster rate under high-pressure gas than under low-pressure gas. These results imply that high-pressure gas enhances surface diffusion.