Sintering characteristics of nanocrystalline TiO₂—A study combining small angle neutron scattering and nitrogen absorption–BET

Small angle neutron scattering (SANS) was employed to characterize the pore structure of nanophase TiO₂ ceramic materials compacted at different temperatures. Nanophase samples, produced by inert gas condensation, were compacted at 25, 290, 413, and 550 °C using a pressure of ≍1 GPa. The pore size distribution of the sample compacted at room temperature was very broad, with sizes ranging from ≍3–30 nm and pores comprising 38% of the sample volume. Compaction at 290 and 413 °C reduced the pore volume to 25% and 20%, respectively, by eliminating pores at both the small and large ends of the distribution. Compaction at 550 °C resulted in a pore volume that was less than 8%. Complications in the SANS analysis arising from the scattering from grain boundaries are discussed. The results from SANS are compared with those derived from nitrogen absorption, BET, measurements.