掺钙铬酸镧-氧化物复合材料的导电性能研究

基于通用有效介质方程,建立掺钙铬酸镧?氧化物复合材料的电导率模型,研究服役温度、掺钙量、环境气氛和氧化物类型对电导率的影响.结果表明,掺钙LaCrO3?ZrO2中ZrO2的临界体积分数为10％,临界指数为1.71;掺钙LaCrO3?Al2 O3中Al2 O3的临界体积分数为15％,临界指数为1.74.当氧化物体积分数小...

Conductivity of Ca-doped LaCrO3-Oxide Composite

A conductivity calculation model for the Ca-doped LaCrO₃-oxide composite was established based on a general effective medium equation, and used to investigate the effects of service temperature, Ca-doped content, atmosphere and oxide type on the conductivity of composite. The results show that the critical volume fraction (that is percolation threshold) of the ZrO₂ for the conductivity of Ca-doped LaCrO₃-ZrO₂ composite is 10% and the critical exponent is 1.71; while the percolation threshold of the Al₂O₃ for the conductivity of Ca-doped LaCrO₃-Al₂O₃ composite is 15% and the critical exponent is 1.74. When the volume fraction of the oxides is less than the critical volume fraction, the conductivity of the composite gradually decreases with the increase of temperature; when the volume fraction of oxides is much greater than the critical volume fraction, the conductivity increases sharply with the increase of temperature. The conductivity of composite increases gradually with the increasing of the Ca doping amount, and the conductivity of the composite in H₂ atmosphere at a lower temperature is significantly lower than that in air atmosphere. It is shown that the doping of ZrO₂ or Al₂O₃ has brought little effect to the conductivity of the composite.