Comparative study of conventionally and microwave heated dysprosia stabilized zirconia (DySZ)

Present work deals with the comparative study of micro-structural and electrical properties of conventionally and microwave (MW) heat treated dysprosia stabilized zirconia electrolyte for solid oxide fuel cell application. Characterizations have been evaluated by means of X-ray diffraction (XRD) and scanning (SEM), and complex impedance analysis respectively. The amount of dysprosia was varied from 2 to 10 mol% in zirconia. The addition of dysprosia (8-10 mol % in conventionally sintered DySZ and 4-10 mol% in MW sintered DySZ) stabilized the cubic zirconia phase, which was analyzed from XRD analysis. SEM micrographs clearly showed the grain size but high density in MW sintered DySZ compare to conventionally sintered DySZ compounds. Complex impedance analysis was performed in the temperature range from 250 to 600℃. The results indicated a dominant contribution comes from grain boundary resistance by both ways heat treated DySZ samples. D.C. conductivity increases with dysprosia doping up to 6 mol% (conventional sintered) and 8 mol% (for MW sintered) and thereafter showing a reverse trend. Magnitude of DC conductivity found to be higher in MW sintered DySZ than conventional DySZ. (author)