Microwave sintering of zirconia-yttria electrolytes and measurement of their ionic conductivity
Abstract Yttria-zirconia electrolytes of 3 and 8 mol% Y 2 O 3 nominal content have been prepared by sintering in a microwave furnace under several different conditions to obtain crack-free high density specimens. The ionic conductivity of both compositions has been investigated with a four-probe DC technique as a function of temperature over the 400 °–1000 °C range and as a function of time at the normal fuel cell operating temperature of 1000 °C. Impedance spectroscopy has been used to separate the grain boundary contribution to the total resistivity. The results have been compared with conventionally sintered (radiant heat) materials.