Mn掺杂对La_(0.68)Pb_(0.32)FeO_3纳米材料电阻率、气敏性能的影响

The Effect of Resistivity and Gas-Sensing Property for La_(0.68)Pb_(0.32)FeO_3 Doped with Mn

采用Sol-gel法合成了系列纳米材料La0.68Pb0.32Fe1-xMnxO3(x=0.0,0.1,0.2,0.4,0.6),研究了Mn掺杂对材料的导电特性和气敏特性的影响。研究表明:合成的系列纳米材料均具有正交钙钛矿结构,Mn的掺杂对材料La0.68Pb0.32FeO3的结构没有影响,且对材料粒径的影响较小;随Mn元素含量的增加,La0.68Pb0.32Fe1-xMnxO3纳米粉体对丙酮的气敏性均迅速降低;Mn掺杂同时导致电阻率减小,这是由于形成Mn3+—O2-—Mn4+双交换作用键的缘故。

The samples La0.68Pb0.32Fe1-xMnxO3 （x=0.0, 0.1, 0.2, 0.4 and 0.6） were prepared using sol-gel method. The X-ray diffraction patterns indicate that samples La0.68Pb0.32Fe1-xMnxO3 （x=0.0, 0.1, 0.2, 0.4 and 0.6） all have orthorhombic perovskite structure. With the increase of composition x, the resistivity for samples La0.68Pb0.32Fe1-xMnxO3 are decreased rapidly due to forming the bond Mn^3＋-O2^-Mn^4＋ double-ekchange interaction. The gas-sensing property for samples La0.68Pb0.32Fe1-xMnxO3 is also decreased rapidly with increasing composition x, but the grain sizes are not effected obviously.