Dehydration kinetics of nano-YSZ ceramics monitored by in-situ infrared spectroscopy

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.