Abstract n-type Mg3Sb2–Mg3Bi2 alloy shows as a potential new thermoelectric material (TE) and has been widely researched recently. The pure phase n-type Mg3·20(Sb0·3Bi0.7)1.99Te0.01 were prepared by adjusting Mg content with the Bi impurity phase being effectively suppressed. Then, Co element was doped into the pure phase and the electrical conductivity of samples were improved. With a high power factor of 20.3 μW cm−1K−2 for Mg3·185Co0·015(Sb0·3Bi0.7)1.99Te0.01 at 525 K. Additionally, it was found that the phonon scattering is enhanced due to the larger atomic mass of Co comparing to Mg and the lattice thermal conductivity is reduced. As a result, a high ZT value of ~ 1.03 at 525 K is achieved for the Mg3·185Co0·015(Sb0·3Bi0.7)1.99Te0.01.

中文翻译：

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Co元素掺杂改善n型Mg3Sb2-Mg3Bi2合金的热电性能

摘要 n 型Mg3Sb2-Mg3Bi2 合金是一种具有潜力的新型热电材料（TE），近年来得到了广泛的研究。通过调节Mg含量，有效抑制Bi杂质相，制备纯相n型Mg3·20(Sb0·3Bi0.7)1.99Te0.01。然后，在纯相中掺杂 Co 元素，提高了样品的电导率。Mg3·185Co0·015(Sb0·3Bi0.7)1.99Te0.01 在 525 K 具有 20.3 μW cm-1K-2 的高功率因数。此外，发现声子散射由于较大的原子而增强与 Mg 相比，Co 的质量降低，晶格热导率降低。因此，Mg3·185Co0·015(Sb0·3Bi0.7)1.99Te0.01 在 525 K 下实现了 ~ 1.03 的高 ZT 值。