A new semiconductor Al2Fe3Si3 with complex crystal structure
A new semiconductor Al2Fe3Si3 with complex crystal structure
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DOI：
10.1016/j.intermet.2017.05.019
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发表时间：
2017-10-01
期刊：
影响因子：
4.4
通讯作者：
Yamanaka, Shinsuke
中科院分区：
文献类型：
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作者：
Shiota, Yasutaka;Muta, Hiroaki;Yamanaka, Shinsuke
采用电弧炉熔炼、放电等离子烧结、热处理的方法合成了具有复杂三斜结构的新型半导体材料Al2Fe3Si3。改变了样品的名义成分以补偿合成过程中Al的蒸发，得到了单一的Al2Fe3Si3相，其名义成分为Al：Fe：Si=26：37：37(相对于化学计量比，Al过量为6at.%)。在本研究中，我们测量了新型半导体Al2Fe3Si3的声速、热膨胀系数、维氏硬度、断裂韧性、电导率、塞贝克系数和热导率。Al2Fe3Si3样品在300~850K具有正的Seebeck系数，在430K时的最大Seebeck系数为110muV/K；Al2Fe3Si3的德拜温度为640K，与其他Al、Fe、Si基热电材料相似或更高，但由于Al2Fe3Si3复杂的晶体结构，其晶格热导率较低，为4~5W/mK。在580K时，ZT值最大为0.06。
Al2Fe3Si3, a new semiconductor with complex triclinic structure was synthesized by arc melting and spark plasma sintering, followed by heat treatment. The nominal compositions of samples have been changed to compensate Al evaporation during synthesis process, and single Al2Fe3Si3 phase has been obtained with the nominal composition of Al: Fe: Si = 26: 37: 37 (6 at.% Al excess against stoichiometry). In this study, we measured the sound velocity, thermal expansion coefficient, Vickers hardness, fracture toughness, electrical conductivity, Seebeck coefficient, and thermal conductivity of the new semiconductor Al2Fe3Si3. The Al2Fe3Si3 sample displayed positive Seebeck coefficient from 300 to 850 K, with a maximum Seebeck coefficient of 110 mu V/K at 430 K. The Debye temperature of Al2Fe3Si3 was 640 K, which was similar to or higher than those of other Al, Fe, Si based thermoelectric materials, but the lattice thermal conductivity was lower, 4-5 W/mK, due to the complex crystal structure of Al2Fe3Si3. The maximum ZT value was 0.06 at 580 K.