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采用柠檬酸溶胶凝胶结合陶瓷烧结工艺制备了Ca位掺杂稀土的Ca0.95RE0.05MnO3(RE=Pr,Eu,Tb)氧化物块体试样,并通过X射线衍射、扫描电子显微镜及电输运参数测试仪分析了所得试样。结果表明:所有试样呈单一物相,掺杂氧化物晶胞减小,块体试样结构致密;未掺杂的CaMnO3呈半导体传输特性,其电阻率较高,在373K时达340 mΩ.cm;Ca位掺杂稀土元素Pr,Eu,Tb之后,其电阻率大幅度降低,但各温度点电阻率随Pr,Eu,Tb略有升高;测试温度范围内所有掺杂试样载流子激活能降低,输运特性未发生改变;其中Pr掺杂试样Ca0.95Pr0.05MnO3各温度点的电阻率最低,在373K时为最低8 mΩ.cm,远低于未掺杂氧化物。
The samples of Ca0.95RE0.05MnO3 (RE = Pr, Eu, Tb) oxide with rare-earth doped Ca were prepared by citric acid sol-gel combined with ceramic sintering process. The samples were characterized by X-ray diffraction, scanning electron microscopy The transport parameter tester analyzed the resulting sample. The results show that all the samples have a single phase, and the unit cell of doped oxide decreases and the bulk sample has a compact structure. The undoped CaMnO3 has a semiconducting transport characteristic with a high resistivity of 340 mΩ at 373K. cm; the resistivity of rare earth elements Pr, Eu, Tb doped with Ca significantly decreased, but the resistivity of each temperature point slightly increased with Pr, Eu, Tb; all doped samples in the temperature range The activation energy can be reduced and the transport properties have not changed. Among them, the resistivity of the Pr doped sample Ca0.95Pr0.05MnO3 is the lowest, and the lowest is 8 mΩ.cm at 373K, much lower than the undoped oxide.