Enhanced thermoelectric properties in MgAgSb composite with Ag3Sb fabricated by the microwave-assisted process and subsequent spark plasma sintering
Enhanced thermoelectric properties in MgAgSb composite with Ag3Sb fabricated by the microwave-assisted process and subsequent spark plasma sintering
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DOI：
10.1080/17436753.2019.1705018
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发表时间：
2019-12
影响因子：
2.2
通讯作者：
Suwei Li;Junyou Yang;Yong Liu;Jiwu Xin;Sihui Li;Qiang Long;Q. Jiang
中科院分区：
文献类型：
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作者：
Suwei Li;Junyou Yang;Yong Liu;Jiwu Xin;Sihui Li;Qiang Long;Q. Jiang
MgAgSb材料因其无毒、原料元素丰富而受到越来越多的关注。我们在此利用微波辅助工艺和放电等离子烧结来制造 MgAgSb 样品。与熔融法制备的样品不同，微波辅助法制备的MgAgSb基体中存在Ag3Sb第二相。 Ag3Sb 明显增加载流子浓度并导致低电阻率和高功率因数。最大功率因数约为2000 μWm−1 K−2，比熔化法制备的MgAgSb样品的功率因数大一倍。在微波辅助过程中，基体中引入了许多堆垛层错和刃位错，导致出现厚度为0.5-1μm的片状亚晶。这些缺陷增强了声子的散射并降低了晶格热导率。与熔融工艺制备的样品相比，输运特性的解耦导致 ZT 值（∼0.76@548 K）提高了 20%。
MgAgSb material has been attracting more attention for its non-toxicity and elemental abundance of raw materials. We herein utilise the microwave-assisted process and spark plasma sintering to fabricate MgAgSb samples. Different from the sample prepared by the melting process, there is an Ag3Sb second phase in the matrix of MgAgSb prepared by the microwave-assisted process. Ag3Sb obviously increases carrier concentration and leads to low electrical resistivity and high power factor. The maximum power factor is about 2000 μWm−1 K−2, which is double larger than that of MgAgSb sample prepared by the melting process. During the microwave-assisted process, many stacking faults and edge dislocations are introduced into the matrix which leads to the appearance of flake sub-grains with a thickness of 0.5–1 μm. These defects strengthen phonons’ scattering and reduce the lattice thermal conductivity. The decoupling of transport properties leads to 20% enhancement of ZT value (∼0.76@548 K), compared with the sample prepared by the melting process.