Journal article

Publication year: 2022

Pages: 21716-21726

Journal: Journal of Materials Chemistry A: materials for energy and sustainability

Volume number: 10

Issue number: 40

ISSN: 2050-7488

eISSN: 2050-7496

Open access status: Hybrid

DOI Link: https://doi.org/10.1039/d2ta05936c

Publisher: Royal Society of Chemistry

Abstract: 
alpha-MgAgSb is a promising p-type thermoelectric (TE) with excellent performance from room temperature up to 300 degrees C with a figure of merit of zT(max) = 1.3. This makes MgAgSb a potential Te-free bismuth telluride (Bi2Te3) substitute for cooling and waste heat conversion applications. However, the material is also known for its sensitivity on synthesis conditions as indicated by various reports on the same nominal composition which show greatly differing TE properties and performance. This indicates a fundamental lack of synthesis control and synthesis-composition-property relationship knowledge. In this work, we establish a modified synthesis route with improved control over the effective sample stoichiometry which allows for reproducible high-performance properties (zT(max) = 1.34 +/- 0.19 at 561 K) and for systematically targeting different thermodynamic states of MgAgSb. This phase boundary mapping reveals that the homogeneity range for MgAgSb is very small (<0.1 at%) and that the TE properties are not governed by different thermodynamic states. Instead, we rationalize that the TE performance of MgAgSb is mainly controlled by the amount and type of secondary phases, mainly affecting the carrier mobility. We conclude that Sb-excess related secondary phases are the least detrimental, leading the way to upscaled synthesis of high-performance material.

Harvard Citation style: Duparchy, A., Millerand, L., Camut, J., Tumminello, S., Kamila, H., Deshpande, R., et al. (2022) Establishing synthesis-composition-property relationships for enhanced and reproducible thermoelectric properties of MgAgSb, Journal of Materials Chemistry A: materials for energy and sustainability, 10(40), pp. 21716-21726. https://doi.org/10.1039/d2ta05936c

APA Citation style: Duparchy, A., Millerand, L., Camut, J., Tumminello, S., Kamila, H., Deshpande, R., Cowley, A., Mueller, E., & de Boor, J. (2022). Establishing synthesis-composition-property relationships for enhanced and reproducible thermoelectric properties of MgAgSb. Journal of Materials Chemistry A: materials for energy and sustainability. 10(40), 21716-21726. https://doi.org/10.1039/d2ta05936c