The formation of thermal vacancies in icosahedral Zn65Mg25Er10 quasicrystals was studied, from room temperature to about 720K, by means of positron annihilation spectroscopy; using 2-detector coincident Doppler broadening techniques. Significant vacancy formation was observed for homologous temperatures higher than 0.6. An apparent vacancy formation enthalpy of 1.2eV was determined. The results were explained in terms of high-temperature vacancy processes in quasicrystals and other complex solids. High-Temperature Vacancy Studies of Icosahedral Zn65Mg25Er10 Quasicrystal. F.Ye, W.Sprengel, X.Y.Zhang, E.Uhrig, W.Assmus, H.E.Schaefer: Journal of Physics - Condensed Matter, 2004, 16[9], 1531-7