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用四电极法研究了 BaCo0．7 Fe0．2 Nb0．1 O 3-δ(BCFN)离子-电子混合导体的总电导率随温度的变化规律；通过阻塞电极法测量了 BaCo0．7 Fe0．2 Nb0．1 O 3-δ氧离子电导率随温度的变化规律；通过计算得到了电子电导率随温度的变化规律.研究结果表明,在温度低于550℃以下时,电子电导起了决定作用,随着温度的升高总电导率和电子电导率均呈现出显著增加的趋势,表现为 P 型半导体特征；当温度在550~650℃时,由于晶格氧的脱附,消耗了自由电子,导致电子电导率略有下降,使得总电导率表现出类似的变化规律,通过计算得到在550℃以下 BCFN 混合导体的电子电导的表观活化能为0．30 eV；当温度高于650℃以上时,由于氧空位增加导致氧离子电导率随温度升高迅速增大,使得总电导率又呈现增加的趋势,计算得到氧离子迁移活化能为1．18 eV；O 2-TPD 研究结果证明了在550~650℃时存在明显的晶格氧的脱附峰,晶格氧的脱附显著影响了 BCFN 混合导体电子电导率和总电导率.当温度低于650℃以下时,电子的迁移数接近100％,当温度高于650℃以上时,氧离子的迁移数迅速增大,900℃氧离子迁移数可达到8．97％.

In this paper,the rules of conductivity of BaCo0.7 Fe0.2 Nb0.1 O 3 -δ(BCFN)ionic-electric mixed conductor changing with temperature was studied by the four-probe method;the ionic conductivity of BCFN changing with temperature was obtained by the electrode-blocking method and then calculated the electric conductivity.As our results revealed,the electric carriers play an dominant effect in the conductor and electronic transport number was near 100% when the temperature was below 550 ℃.The whole conductivity and electric conductivity in-crease rapidly with the evaluating temperature,which exhibits a characteristic of P-type semi-conductor with the apparent electric activation energy of 0.30 eV.When the temperature is at the range of 550-650 ℃,the elec-tric conductivity decreases because of electric carrier consumption resulting from the lattice oxygen desorption. Since the oxygen vacancy increases when the temperature was above 650 ℃,the ionic conductivity and oxide-ionic transport number increase rapidly with rising temperature and enhance the whole conductivity as well.The oxide-ionic transport number was up to 8.97% at 900 ℃.The calculated migration activation energy of oxygen vacancy here was 1.18 eV.Moreover,the desorption peak observed in the O 2 -TPD experiment at the range of 550-650 ℃ provides a powerful proof of the lattice oxygen desorption,which make a remarkable effect on the ionic conductivity and whole conductivity of BCFN.