中文摘要：

采用低温燃烧合成技术制备了La0.8Sr0.2CU1-yFeyO2.5-δ（y=0．1-0．4）粉体。分别利用X射线衍射（XRD）和差热分析（DTA）技术对粉体的性能进行了表征。XRD结果表明，经800℃焙烧的La0.8Sr0.2CU1-yFeyO2.5-δ均为四方钙钛矿结构，晶体结构参数之间满足关系式a=b≈2√2c，但当Fe掺杂量在0.25以上时，生成了新相La0.16Sr0.84FeO3，且随着Fe含量的增加，La0.16Sr0.84FeO3的生成量也增多,DTA结果显示La0.8Sr0.2CU1-yFeyO2.5-δ在1000℃以下是热力学稳定的，不会发生分解反应,采用直流四电极法测试了La0.8Sr0.2CU1-yFeyO2.5-δ试样在100-800℃之间的电导率。试样的电导率1n（δT）与1／T之间呈很好的线性关系，说明La0.8Sr0.2CU1-yFeyO2.5-δ在测试温度范围内服从小极化子导电机制。Fe的掺杂量对电导率和电导活化能有着明显的影响，随着Fe掺杂量的增加，La0.8Sr0.2CU1-yFeyO2.5-δ的电导率降低，电导活化能增大。

英文摘要：

La0.8Sr0.2CU1-yFeyO2.5-δpowders were synthesized by a low temperature combustion method. The as-synthesized powders were characterized by X-ray diffraction analysis （XRD） and differential thermal analysis （DTA）. The XRD patterns show that La0.8Sr0.2CU1-yFeyO2.5-δ powders calcined at 800℃ are in the tetragonal perovskite phase, obeying the relationship of a=b≈2√2c between the lattice parameters. A new phase La0.16Sr0.84FeO3 is emerged for y≥0.25, and the amount of La0.16Sr0.84FeO3 phase increases with increasing Fe substitution. DTA results indicate that the perovskites of La0.8Sr0.2CU1-yFeyO2.5-δ is thermodynamically stable below 1000℃. The electrical conductivity of La0.8Sr0.2CU1-yFeyO2.5-δ was measured by the four-point method at 100-800℃. The linear plots of In（δT） vs 1/T indicate that the electronic conduct via a small polaron hopping mechanism in the testing temperature range. The electrical conductivity and activation energy of La0.8Sr0.2CU1-yFeyO2.5-δ are closely dependent on Fe substitution. The electrical conductivity decreases and activation energy increases with increasing Fe substitution.