| Yttria stabilized zirconia (YSZ) as an important oxygen ion conductor, is widely used in the field of solid oxide fuel cell, solid electrolyte oxygen sensor and oxygen concentration analyzer. Based on the conditions for lacking of the more suitable electrolyte, it has the important practical significance to expand the scope of the application and the improvement of the use of performance by further enhance the oxygen ion conductivity of YSZ in low temperature.We prepared the8YSZ-SrTiO3composite ceramic for different proportion and sintering temperature by solid-state sintering method, analyzed the phase composition and crystal structure of the composite ceramic with XRD,SEM and TEM,and tested the DC conductivity and AC impedance of the composite ceramics at300℃-800℃, the results show that:the solid phase reaction of8YSZ and SrTiO3occurs at high temperature, and the degree of reaction associated with the sintering temperature and doping content of SrTiO3; with the SrTiO3doping concentration increases, the relative density of the composite ceramic decreases; the conductivity activation energy of the composite ceramic is slightly higher than that of leV, which is accord with the ion conductors, and the measured ionic mobility of all the composite ceramics is greater than99%, demonstrated the nature of the conductivity of composite ceramics for ionic conductance;it has enhanced the oxygen ion transport by doping SrTiO3to take in the heterogeneous phase interface, but the presence of the non conduction phase and the solid phase reaction between the two phases also hindered the conductivity enhancement, then the final result is that the conductivity of composites increased first and then decreased with the increased of the concentration for SrTiO3, and the highest conductivity appears when the SrTiO3concentration is about2.5vol.%. |
PDF Full Text Request