Study on surface defect structures of ZrO 2 and some doped ZrO 2 by means of work function measurement

Abstract

The work function change of the ZrO 2 + 2%Y 2O 3 sintered pellet, caused by a change of the composition of the sweep gas, was measured using a high temperature Kelvin probe. The Pt reference electrode was calibrated by using ZrO 2 + 2%Y 2O 3 as a standard material. Work function changes of undoped ZrO 2 and Nb-doped ZrO 2 (2%Nb 2O 5) were measured as a function of equilibrium oxygen partial pressure, P O2. The thus obtained exponents of P O2, 1/ n, were 1/6.2 and 1/33.6 for ZrO 2 and ZrO 2 + 2%Nb 2O 5, respectively. These exponent values were discussed in terms of defect chemistry of the surface layer.