Almond D.P.Çallica H.West A.R.2019-10-272019-10-2719810025-54080025-5408https://doi.org/10.1016/0025-5408(81)90187-2https://hdl.handle.net/11454/28541Measurements are presented of the relative attenuation of longitudinal stress waves, of frequencies from 10 to 70 MHz, in polycrystalline samples of ß ß¨ alumina at temperatures from 80 to 300 K. The attenuation is found to exhibit a series of internal friction peaks, attributed to an interaction with Na+ ion diffusion. The activation energy for the diffusion of Na+ in the sample is estimated to be 0.142 eV. Shear wave attenuation is also found to rise at temperatures of ~300 K in samples contaminated by water absorption. © 1981.en10.1016/0025-5408(81)90187-2info:eu-repo/semantics/closedAccessArticle161117124Q1