Published online by Cambridge University Press: 01 February 2011
We have investigated the effect of various dopants on the sintering characteristics of Ce0.9Gd0.1O1.95 (CGO) and found that 99% dense electrolyte pellets can be produced at the record low temperature of 800°C (as opposed to the 1400°C typically needed) by sintering Ce0.9Gd0.1O1.95 with as little 3mol% lithium. Our studies indicate that doping the CGO surface with lithium nitrate, as opposed to using alternative lithium salts, produces the largest decrease in sintering temperature. Unlike other dopants that lower the sintering temperature by altering the near grain boundary vacancy concentration, lithium lowers the sintering temperature through the formation of an intergranular liquid phase. This liquid phase allows fully dense, completely constrained CGO films to be produced on inert substrates at temperatures as low as 950°C.