Thermal expansion and Debye temperature of rare earth-doped ceria

Thermal expansions of un-doped ceria and rare earth-doped ceria (Ce1-xMxO2-x/3, M=La, Sm, Dy, Yb) were measured in the temperature range from 100 to 800 K by TMA. Debye temperature, of these compounds were measured at room temperature by all ultrasonic Pulse method. The thermal expansion coefficients of rare earth-doped CeO2 increased with increasing ionic radius of doped ions and its M content expect Dy ion. The Debye temperature of rare earth-doped ceria estimated from the longitudinal and transverse sonic wave velocities decreased with increasing M content, probably due to generation of oxygen vacancy by doping the rare earth elements. The relation between thermal expansion coefficient and Debye temperature was discussed. (c) 2005 Elsevier B.V. All rights reserved.