摘要
NaCo2O4是氧化物热电材料的典型代表,也是目前人们研究较多的一种热电材料,本文采用固相反应法和溶胶-凝胶法对NaCo2O4以及Na位掺杂K、Ca、Sr、Ce试样进行制备研究.选择合适的工艺参数,采用快速升温法,可获得纯度较高(大于94%)的NaCo2O4,并使掺杂元素K、Ca、Sr进入到NaCo2O4晶格中,而Ce由于原子半径太大,难以掺杂入NaCo2O4晶格.实验结果表明采用柠檬酸溶胶-凝胶法比固相反应法制备的试样晶粒尺寸更细小,增加声子散射,使晶格热导率降低,由此提高材料的热电优值,进一步改善材料的热电性能.
The solid reaction method and Sol -Gel method were used to prepare thermoelectric materials NaCo2O4 and its the Na-site doping by K,Ca,Sr and Ce. By optimizing appropriate parameters and fast increasing the temperature, NaCo2O4 with high purity of more than 94% was obtained. K,Ca and Sr were in the crystal lattice of NaCo2O4 excluding Ce due to its larger atomic diameter. Experimental results show that NaCo2O4 prepared by citric acid Sol - Gel approach was with smaller particle size, higher strength of phonon dispersion, lower thermal conductance and better thermoelectric figure of merit, which improves the thermoelectric properties of materials.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2008年第3期419-422,共4页
Materials Science and Technology
基金
辽宁省自然科学基金资助项目(20042018)
关键词
热电材料
固相反应
溶胶凝胶法
掺杂
NaCo2O4
制备
thermoelectric materials
solid state reaction
Sol - Gel method
doping
NaCo2O4
preparation
