Transport properties of the layered Zintl compound SrZnSb_2
Abstract
Transport properties of the layered Zintl compound SrZnSb_2 have been characterized from room temperature to 725 K on polycrystalline samples. SrZnSb_2 samples were found to be p-type with a Hall carrier concentration of 5×10^(20) cm^(−3) at room temperature, and a small Seebeck coefficient and electrical resistivity are observed. A single band model predicts that, even with optimal doping, significant thermoelectric performance will not be achieved in SrZnSb_2. A relatively low lattice thermal conductivity is observed, κ_L~1.2 W m^(−1) K^(−1), at room temperature. The thermal transport of SrZnSb_2 is compared to that of the layered Zintl compounds AZn2Sb_2 (A=Ca,Yb,Sr,Eu), which have smaller unit cells and larger lattice thermal conductivity, κ_L~2 W m^(−1) K^(−1), at 300K. Ultrasonic measurements, in combination with kinetic theory and the estimated κ_L values, suggest that the lower κ_L of SrZnSb_2 is primarily the result of a reduction in the volumetric specific heat of the acoustic phonons due to the increased number of atoms per unit cell. Therefore, this work recommends that unit cell size should be considered when selecting Zintl compounds for potential thermoelectric application.
Additional Information
©2009 American Institute of Physics. Received 16 April 2009; accepted 30 May 2009; published 9 July 2009. The Beckman Foundation is thanked for financial support. 72.15.Gd Galvanomagnetic and other magnetotransport effects (metals/alloys) 72.15.Jf Thermoelectric and thermomagnetic effects (metals/alloys) 72.15.Eb Electrical and thermal conduction in crystalline metals and alloys 63.20.-e Phonons in crystal lattices 65.40.Ba Heat capacity of crystalline solidsAttached Files
Published - May2009p5160J_Appl_Phys.pdf
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Additional details
- Eprint ID
- 15249
- Resolver ID
- CaltechAUTHORS:20090821-144737639
- Arnold and Mabel Beckman Foundation
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2009-09-09Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field