Dy掺杂Ca1-x Dyx MnO3(x=0,0.02,0.03,0.05,0.10)热电材料的Rietveld精修及高温热电性能研究

本文采用共沉淀法制备Dy掺杂Ca_1-xDy_xMnO₃(x=0,0.02,0.03,0.05,0.10)热电材料,通过X射线衍射对热电材料进行物相结构表征,利用Rietveld粉末衍射全谱拟合方法对X射线衍射数据进行精修得到Dy掺杂Ca_1-xDy_xMnO₃(x=0,0.02,0.03,0.05,0.10)热电材料的精细结构,利用标准四探针法测试高温热电性能.Rietveld精修结果表明,随着Dy掺杂量的增加,CaMnO₃样品的晶胞参数及晶胞体积逐渐变大.对应的电阻率测量结果表明,掺杂样品的电阻率随着Dy掺杂量的增加而减小.其中Ca_0.9Dy_0.1MnO₃的室温电阻率最低,为6.7×10^-5 Ω·m,是未掺杂CaMnO₃的1/6倍.

Study on Rietveld Refinement and High-temperature Thermoelectric Properties of Dy Doped Ca1-xDyxMnO3(x=0,0.02,0.03,0.05,0.10)Thermoelectric Materials

Dy doped Ca1-xDyxMnO3(x=0,0.02,0.03,0.05,0.10)thermoelectric materials were prepared by coprecipitation.The phase structure was determined by X-ray diffraction.Fine structure of Dy doped Ca1-xDyxMnO3(x=0,0.02,0.03,0.05,0.10)thermoelectric materials were obtained by refining data with Rietveld powder diffraction full spectrum fitting method.And the high-temperature thermoelectric properties were determined by four probe electrodes.Rietveld refinement results show that the cell parameters and cell volume of CaMnO3 samples gradually increase with the increase of Dy doping.The corresponding resistivity results show that the resistivity of the doped samples decreases with the increase of Dy doping.The room temperature resistivity of Ca0.9Dy0.1MnO3 is the lowest,which is 6.7×10^-5Ω·m,1/6 times of that of undoped CaMnO3.