Photoacoustic study of the effect of hydroxyl ion on thermal diffusivity of gamma alumina

The effect of the chemisorbed hydroxyl groups on the thermal diffusivity of gamma alumina is determined by evaluating the thermal diffusivity at vario us degassing temperatures and by doping it with rare earth oxide using phot oacoustic technique. The thermal diffusivity is found to decrease with the increase in degassing temperature as well as with the increase in the dopin g concentration of rare earth oxide. This decrease has been attributed to t he loss of hydroxyl ion from the gamma-Al2O3. (C) 1999 American Institute o f Physics. [S0021-8979(99)08202-X].