Kazuhisa SATO
Tohoku University, Japan
Title: Strength, elastic and electrical properties of non-stoichiometric materials under various Oxygen partial pressures
Biography
Biography: Kazuhisa SATO
Abstract
Fracture strength and Young’s modulus of ceria doped with 10 mol.% Gd and 10, 20 and 30 mol.% Y were investigated by means of small punch testing method under controlled the temperature (1073 K) and the oxygen partial pressure (log((p(O2)/atm)= -1.1, 17.5, -21.4, -22.0). Under the reducing conditions, the color of fractured doped ceria specimen changed from pale yellow to gray, it is therefore indicated that oxygen nonstoichiometry affects mechanical properties of the doped ceria. Under the low oxygen partial pressure the Young’s modulus of all the specimens decreased monotonically. The fracture strength, by contrast, increased at log(p(O2)/atm) = -17.5, and under the lower oxygen partial pressure, different variation trends showed each yttria doped cerias with Y contents. The oxygen partial pressure dependence of the fracture strength of doped ceria could be arranged as a function of the reduction expansion of the lattice constant a/a0.