Regulating thermoelectric properties of Eu0.5Ca0.5Zn2Sb2 through Mg dopant

• Published in: Materials today energy 2022-08, Vol.28, p.101071, Article 101071
• Main Authors: Le, Wenkai, Sheng, Wenwen, Liu, Runtao, Yuan, Minhui, Yang, Wenwei, Lv, Jingyi, Yin, Li, Chen, Chen, Wang, Xinyu, Zhang, Zongwei, Liu, Kejia, Wang, Tianchi, Zhang, Qian, Shuai, Jing
• Format: Article
• Language: English
• Subjects: Mechanical alloying; Thermal conductivity; Thermoelectric materials; Zintl phase
• ISSN: 2468-6069; 2468-6069
• DOI: 10.1016/j.mtener.2022.101071

CaAl2Si2 structure Zintl compounds are promising thermoelectric materials and have been extensively studied recently. In this study, Eu0.5Ca0.5Zn2-xMgxSb2 (0 ≤ x ≤ 0.3) compounds have been prepared by ball milling and spark plasma sintering. Results show that for Eu0.5Ca0.5Zn2Sb2, ZT has been improved about 20% compared with previously reported thermoelectric properties through the ball milling and hot-pressing preparation process. Moreover, the thermoelectric performance of Eu0.5Ca0.5Zn2Sb2 can be further increased through Mg substitution. Mg replacing Zn has a strong impact on phonon scattering, resulting in low thermal conductivity. A highest ZT about 1.05 is obtained in the Eu0.5Ca0.5Zn1.8Mg0.2Sb2 sample at 773 K. The obtained high thermoelectric performance in our work is comparable with other p-type Zintl thermoelectric materials, and this work provides a reference for the improvement of properties of other CaAl2Si2 structure Zintl thermoelectric materials. [Display omitted] •Ball milling and spark plasma sintering method enhances ZT of Eu0.5Ca0.5Zn2Sb2 by ∼20%.•Mg replacing Zn has a strong impact on phonon scattering, resulting in low thermal conductivity.•A highest ZT ∼1.05 at 773 K is obtained in Eu0.5Ca0.5Zn1.8Mg0.2Sb2.