Mixed Ionic Electronic Conduction in Mn/Mo Doped Ganolinum Titanate

摘要

Recent work has shown that Gd_2(Ti_(1-x)MO_x)_2O_7(GT-Mo) exhibits high levels of mixed conduction under reducing atmospheres, making it suitable as an naode in a solid oxide fuel cell, but not as a cathode since it decomposes at high Po_2. We have succeeded in extending the stability limits of GT-MO to higher Po_2 with the addition of MN. Our earlier studies on Gd_2(mo_yMn_(1-x))_xTi_(1-x))_2O_7(GMMT) as a function of Po_2, T, and compositon utilizing impedance spectroscopy and X-ray diffraction are extended to include a wider range of compsitions. In addition, a new sintering method for the GMMT material is introduced that ocmpensates for observed materials loss and abnormal conduction behavior in previous studies. Defect models explaning the dependence of the conductivity on oxygen partial pressure, temprature, and composition are presented as well.