The sintering of thin, nanocrystalline TiO2 films either 140 or 65 nm thick
is characterized and compared with the sintering of bulk material. Grain s
ize, pore size distribution, and density data are obtained. Observation of
the microstructural evolution during sintering suggests that grain growth,
as well as pore growth, at low density can be attributed to differential si
ntering, ii continuum mechanical model for the intermediate stage is useful
until the grain size becomes one-half the film thickness. From then on, th
e ratio of grain size to film thickness affects the degree by which both de
nsification and grain growth decrease, as compared with the continuum compu
tation results.