Oxygen self-diffusion in cerium oxide doped with Nd

Polycrystalline Ce0.77Nd0.23O1.885 having a relative density in excess of 9 8% was prepared. Oxygen diffusion experiments were performed for the temper ature range from 750 to 1100 degreesC, in an oxygen partial pressure of 6.6 kPa. The concentration profile of O-18 in the specimens following diffusio n annealing was measured by secondary ion mass spectroscopy (SIMS). The oxy gen self-diffusion coefficient obtained using secondary ion mass spectromet ry was expressed by D = 6.31 x 10(-9) exp(-53 kJ mol(-1)/RT) m(2) s(-1) and was in the extrinsic region. The oxygen diffusion coefficient of Ce0.77Nd0 .23O1.885 was larger than that of Ce0.8Y0.2O1.90; it was close to those of Ce0.6Y0.4O1.80 and Ce(0.69)Gcb(0.31)O(2-delta). The oxygen diffusion coeffi cient obtained by the tracer method at 700 OC agreed with that calculated f rom the electrical conductivity in Ce0.77Nd0.23O1.885. The activation energ y of the surface exchange coefficient was 94 kT mol(-1), and the values of the surface exchange coefficient were similar to those of stoichiometric Ce O2 and ThO2.