Abstract: The nanocrystalline TiO₂ ultrafine powders in anatase phase were prepared in 16nm, 26nm
by means of a sol-gel method. The particle sizes and the crystallographic phase were determined. Heat capacities in the temperature range of
78～370K were also measured, and the polynomial equations expressing the change of heat capacity with temperature were fitted. The obtained
values of the heat capacity were compared with those of the coarse crystal from the literature. The relationship between heat capacities and the
particle sizes of nanocrystalline TiO₂ were demonstrated in the view of energetics.

Key words: anatase phase TiO₂, nanocrystalline ultrafine powder, sol-gel method, low-temperature heat capacity