摘要
利用B2O3助熔剂法结合热压法制备了Mg2Si0.487-2x Sn0.5(Ga Sb)x Sb0.013(0.04≤x≤0.10)固溶体。X射线衍射结果表明样品呈单相。Sb掺杂有效提高了样品的电导率。随温度升高,Mg2Si0.487-2x Sn0.5(Ga Sb)x Sb0.013(0.04≤x≤0.10)样品的电导率降低而塞贝克系数升高。随Ga Sb含量的增多,样品的电导率呈现出先增大后减小的变化趋势。所有样品中Mg2Si0.287Sn0.5(Ga Sb)0.1Sb0.013具有最低晶格热导率,其室温晶格热导率比Mg2Si0.5Sn0.5[11]低15%。由于电导率较高使Mg2Si0.327Sn0.5(Ga Sb)0.08Sb0.013具有最高热电优值,在720 K达到0.61,显著高于基体Mg2Si0.5Sn0.5[11]的最高热电优值0.019。
Mg2Si0.487-2xSn0.5（GaSb）xSb0.013 （0.04 〈 x 〈 0.10） solid solutions were synthesized by a B203 flux method followed by hot pressing. X-ray power diffraction analysis confirms that single-phased samples are obtained. It is found that the Sb-doping effec- tively enhances the electrical conductivity. The Seebeck coefficients increase while the electrical conductivity decreases for Mg2Si0.487-2XSn0.5（GaSb）xSb0.013 with the increase of temperature. With increasing of GaSb content the electrical conductivity first in- creases and then decreases. Among all the samples, Mg2Si0.287Sn0.5（GaSb）0.1Sb0.013 sample has the lowest lattice thermal conductivity which is about 15% lower than that of Mg2Si0.sSn0.5 [11] at room temperature. A maximum dimensionless figure of merit of 0.61 at 720 K has been obtained for Mg2Si0.327Sn0.5（GaSb）0.08Sb0.013 mainly due to its high electrical conductivity, which is obviously higher than that （0.019 at 540 K） of Mg2Si0.sSn0.5 [11].
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2014年第11期2623-2626,共4页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China(50731006,50971115,51061120455)
关键词
硅化镁
热电性能
热电材料
等电子取代
magnesium silicides
thermoelectric properties
thermoelectric materials
isoelectronic substitution
