Enhanced thermoelectric properties of Zintl phase YbMg2Bi1.98 through Bi site substitution with Sb
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第24期
论文作者：Jing Wang Muchun Guo Jianbo Zhu Dandan Qin Fengkai Guo Qian Zhang Wei Cai Jiehe Sui
文章页码：189 - 194
摘 要：Benefiting from the unique"Phonon-Glass,Electron-Crystal"（PGEC） characteristic,Zintl phases have been considered as a kind of promising thermoelectric materials.For the typical AM2X2compounds with the Ca Al2Si2-type structure,Yb Mg2Bi2has shown competitive thermoelectric performance recently.Nevertheless,the optimization of Yb Mg2Bi2compounds is primarily focused on the substitution on Yb or Mg site.Herein,the Bi site is substituted by isoelectric Sb and the effect on the thermoelectric transport behavior is investigated.The partial substitution reduces the carrier concentration and induces the lattice deformation caused by the different atomic radius and mass between Bi and Sb,further leading to the decreased power factor and thermal conductivity.Fortunately,the reduction extent of the thermal conductivity outperforms that of power factor.Finally,the Sb substitution successfully results in a better thermoelectric performance compared with that of the pristine Yb Mg2Bi1.98.Especially,the calculated energy conversion efficiency （á） of Yb Mg2Bi1.88Sb0.1which also possesses a relatively high output power density reaches the maximum value of 9.8%when Th=873 K,and Tc=300 K,respectively.This work demonstrates that the idea of substitution on anionic site should be a new strategy to achieve better ZT values for AM2X2compounds.
Jing Wang1，Muchun Guo1，Jianbo Zhu1，Dandan Qin1，Fengkai Guo1，Qian Zhang2，Wei Cai1，Jiehe Sui1
1. National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology2. Department of Materials Science and Engineering, Harbin Institute of Technology
摘 要：Benefiting from the unique"Phonon-Glass,Electron-Crystal"（PGEC） characteristic,Zintl phases have been considered as a kind of promising thermoelectric materials.For the typical AM2X2compounds with the Ca Al2Si2-type structure,Yb Mg2Bi2has shown competitive thermoelectric performance recently.Nevertheless,the optimization of Yb Mg2Bi2compounds is primarily focused on the substitution on Yb or Mg site.Herein,the Bi site is substituted by isoelectric Sb and the effect on the thermoelectric transport behavior is investigated.The partial substitution reduces the carrier concentration and induces the lattice deformation caused by the different atomic radius and mass between Bi and Sb,further leading to the decreased power factor and thermal conductivity.Fortunately,the reduction extent of the thermal conductivity outperforms that of power factor.Finally,the Sb substitution successfully results in a better thermoelectric performance compared with that of the pristine Yb Mg2Bi1.98.Especially,the calculated energy conversion efficiency （á） of Yb Mg2Bi1.88Sb0.1which also possesses a relatively high output power density reaches the maximum value of 9.8%when Th=873 K,and Tc=300 K,respectively.This work demonstrates that the idea of substitution on anionic site should be a new strategy to achieve better ZT values for AM2X2compounds.
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