Abstract:The room-temperature dehydration kinetics of dense nano-crystalline yttria-stabilised zirconia (n-YSZ) ceramics and single crystals (s-YSZ) exposed to liquid H₂O has been studied by means of near-infrared (NIR) spectroscopy. Spectra obtained for both samples showed a combination band at 5200 cm^− 1 that was attributed to the fundamental (ν₂ + ν₃) vibration modes of H₂O molecules. No evidence was found for the presence of structurally bonded OH groups in the samples. The loss of H₂O from n-YSZ exposed to air was observed to be significantly slower than from s-YSZ. Identical loss kinetics were found for n-YSZ (and s-YSZ) samples exposed to liquid CH₃OH. Considered together, the results suggest that H₂O (and CH₃OH) are adsorbed on internal surfaces (pores, microcracks) of n-YSZ.