铋掺杂硅化镁材料的制备及热电性能  

Preparation of Bismuth-Doped Magnesium Silicide Material and Its Thermoelectric Properties

作　　者：杨梅君[1,2] 沈强[2] 唐新峰[2] 张联盟[2] 

机构地区：[1]武汉理工大学材料研究与测试中心,武汉430070 [2]武汉理工大学材料,复合新技术国家重点实验室,武汉430070

出　　处：《硅酸盐学报》2011年第10期1603-1607,共5页Journal of The Chinese Ceramic Society

基　　金：国家重点基础研究发展计划(2007CB607501);中央高校基本科研业务费专项资金资助项目

摘　　要：采用放电等离子体烧结方法制备不同含量铋(Bi)(0、0.7%、1.0%、1.5%、2.0%,摩尔分数,下同)掺杂硅化镁(Mg2Si)热电材料,对材料进行物相、结构及热电性能分析。结果表明:Bi在Mg2Si中最佳掺量为1.5%,继续增加会有Mg2Bi3杂相生成;随着Bi掺量的增加,材料电导率σ不断增加,当Bi掺量为1.5%时,在520K,σ出现最大值,继续增加Bi掺量,由于Mg2Si中Bi已饱和,载流子浓度不再随掺量的增加而变化,且生成的Mg2Bi3杂相会对载流子产生一定散射,σ反而下降;Bi掺杂会显著降低材料Seebeck系数α,但不同含量Bi掺杂对α影响不显著;Bi掺杂使材料热导率κ较未掺杂有微弱上升趋势,随Bi含量增加材料热导率不断降低。Mg2Si热电材料在823K、Bi掺量为1.5%时获得最大热电优值ZT,为0.67。Bismuth （Bi）-doped magnesium silicide （Mg2Si） materials were prepared by a spark plasma sintering method. The Bi-doping content in the materials in a mole ratio was 0, 0.7%, 1.0%, 1.5% and 2.0%, respectively. The results indicate that the maximum content of Bi in Mg2Si is 1.5%. The Mg2Bi3 appeared when the doping content was larger than 1.5%. The electrical con- ductivity （a） of all the materials increased with the increase of Bidoping content and the highest tr was obtained at 520 K when the Bi-doping content was 1.5%. a for the Bidoped Mg2Si decreased when Bi-doping content was more than 1.5%, which was contrib- uted to the hinder of Mg2Bi3 particle. The Seebeck coefficient （a） of materials decreased with the Bi-doping content, but the Bidoping content had little effect on a. The thermal conductivity Qc） of the Bi-doped MgeSi was higher than that of the non-doped materials, but decreased with the increase of Bi-doping content. The Mg2Si materials obtained the highest ZT value of 0.67 at 823 K when the Bi-doping content was 1.5%.

关 键 词：铋掺杂 硅化镁 热电性能 放电等离子体烧结法 

分 类 号：TB34[一般工业技术—材料科学与工程]