Substitution Solid Solutions FeGa3−xEx and Their Thermoelectric Properties
Substitution Solid Solutions FeGa3−xEx and Their Thermoelectric Properties
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DOI：
10.1007/s11664-013-2888-1
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发表时间：
2014-06
影响因子：
2.1
通讯作者：
M. Wagner-Reetz;R. Cardoso‐Gil;Y. Grin
中科院分区：
文献类型：
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作者：
M. Wagner-Reetz;R. Cardoso‐Gil;Y. Grin
在这项研究中，我们进行的金属间化合物半导体FeGa 3的镓网站上的替代实验，以调整电荷载流子浓度，并确定所得到的产品的热电（TE）性能。选择等电子物种铝和铟、空穴掺杂锌和电子掺杂锗来寻找合适的取代元素。通过液固反应和随后的放电等离子烧结处理制备样品FeGa 3 −xEx（E= Al，In，Zn，Ge;x= 0.03，0.05，0.06，0.10，0.20）。采用X射线衍射、金相和显微组织分析来确定化学成分，并评估替代元素的适用性。对于固溶体FeGa 3 − xAlx和FeGa 3 − xInx，替代浓度非常低（x≤ 0.02），并且没有改善FeGa 3的TE性能。样品FeGa 3 − xZnx具有预期的p型行为，热导率略低于二元化合物。固溶体FeGa 3 − xGex的TE优值大幅增加，观察到从半导体到金属样行为的转变，热导率额外降低。对于FeGa_（2.80）Ge_（0.20），最大ZT值为0.21。
In this study we performed substitution experiments on the gallium site of the intermetallic semiconductor FeGa3, to adjust the charge carrier concentration, and determined the thermoelectric (TE) properties of the resulting products. Isoelectronic species aluminium and indium, hole-doping zinc, and electron-doping germanium were chosen to find suitable substituent elements. The samples FeGa3−xEx(E= Al, In, Zn, Ge;x= 0.03, 0.05, 0.06, 0.10, 0.20) were prepared by liquid–solid–reaction with subsequent spark plasma sintering treatment. X-ray diffraction, metallographic, and microstructure analysis were used to determine chemical composition and to evaluate the suitability of the substitution element. For solid solutions FeGa3−xAlxand FeGa3−xInxthe substitution concentrations were very low (x≤ 0.02) and did not improve the TE properties of FeGa3. The samples FeGa3−xZnxhad the expectedp-type behaviour and slightly lower thermal conductivity than the binary compound. A substantial increase in the TE figure of merit was achieved for the solid solution FeGa3−xGexfor which transition from semiconducting to metal-like behaviour was observed, with an additional decrease of thermal conductivity. The maximumZTvalue of 0.21 was achieved for the composition FeGa2.80Ge0.20.