Synthesis, Structure, and Thermoelectric Properties of α-Zn3Sb2 and Comparison to β-Zn13Sb10
(2017) In Chemistry of Materials 29(12). p.5249-5258- Abstract
Zn-Sb compounds (e.g., ZnSb, β-Zn13Sb10) are known to have intriguing thermoelectric properties, but studies of the Zn3Sb2 composition are largely absent. In this work, α-Zn3Sb2 was synthesized and studied via temperature-dependent synchrotron powder diffraction. The α-Zn3Sb2 phase undergoes a phase transformation to the β form at 425 °C, which is stable until melting at 590 °C. Rapid quenching was successful in stabilizing the α phase at room temperature, although all attempts to quench β-Zn3Sb2 were unsuccessful. The structure of α-Zn3Sb2 was solved using single crystal diffraction techniques and verified... (More)
Zn-Sb compounds (e.g., ZnSb, β-Zn13Sb10) are known to have intriguing thermoelectric properties, but studies of the Zn3Sb2 composition are largely absent. In this work, α-Zn3Sb2 was synthesized and studied via temperature-dependent synchrotron powder diffraction. The α-Zn3Sb2 phase undergoes a phase transformation to the β form at 425 °C, which is stable until melting at 590 °C. Rapid quenching was successful in stabilizing the α phase at room temperature, although all attempts to quench β-Zn3Sb2 were unsuccessful. The structure of α-Zn3Sb2 was solved using single crystal diffraction techniques and verified through Rietveld refinement of the powder data. α-Zn3Sb2 adopts a large hexagonal cell (R 3-space group, a = 15.212(2), c = 74.83(2) Å) containing a well-defined framework of isolated Sb3- anions but highly disordered Zn2+ cations. Dense ingots of both the α-Zn3Sb2 and β-Zn13Sb10 phases were formed and used to characterize and compare the low temperature thermoelectric properties. Resistivity and Seebeck coefficient measurements on α-Zn3Sb2 are consistent with a small-gap, degenerately doped, p-type semiconductor. The temperature-dependent lattice thermal conductivity of α-Zn3Sb2 is unusual, resembling that of an amorphous material. Consistent with the extreme degree of Zn disorder observed in the structural analysis, phonon scattering in α-Zn3Sb2 appears to be completely dominated by point-defect scattering over all temperatures below 350 K. This contrasts with the typical balance between point-defect scattering and Umklapp scattering seen in β-Zn13Sb10. Using the Debye-Callaway interpretation of the lattice thermal conductivity, we use the differences between α-Zn3Sb2 and β-Zn13Sb10 to illustrate the potential significance of cation/anion disorder in the Zn-Sb system.
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- author
- Lo, Chun Wan Timothy ; Ortiz, Brenden R. ; Toberer, Eric S. ; He, Allan ; Svitlyk, Volodymyr ; Chernyshov, Dmitry ; Kolodiazhnyi, Taras ; Lidin, Sven LU and Mozharivskyj, Yurij
- organization
- publishing date
- 2017-06-27
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Chemistry of Materials
- volume
- 29
- issue
- 12
- pages
- 10 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000404493100028
- scopus:85021413598
- ISSN
- 0897-4756
- DOI
- 10.1021/acs.chemmater.7b01214
- language
- English
- LU publication?
- yes
- id
- d8d0d25a-00cc-4a3a-bdaf-8b33c3d053bf
- date added to LUP
- 2017-07-11 12:18:36
- date last changed
- 2024-08-05 00:51:29
@article{d8d0d25a-00cc-4a3a-bdaf-8b33c3d053bf,
abstract = {{<p>Zn-Sb compounds (e.g., ZnSb, β-Zn<sub>13</sub>Sb<sub>10</sub>) are known to have intriguing thermoelectric properties, but studies of the Zn<sub>3</sub>Sb<sub>2</sub> composition are largely absent. In this work, α-Zn<sub>3</sub>Sb<sub>2</sub> was synthesized and studied via temperature-dependent synchrotron powder diffraction. The α-Zn<sub>3</sub>Sb<sub>2</sub> phase undergoes a phase transformation to the β form at 425 °C, which is stable until melting at 590 °C. Rapid quenching was successful in stabilizing the α phase at room temperature, although all attempts to quench β-Zn<sub>3</sub>Sb<sub>2</sub> were unsuccessful. The structure of α-Zn<sub>3</sub>Sb<sub>2</sub> was solved using single crystal diffraction techniques and verified through Rietveld refinement of the powder data. α-Zn<sub>3</sub>Sb<sub>2</sub> adopts a large hexagonal cell (R 3-space group, a = 15.212(2), c = 74.83(2) Å) containing a well-defined framework of isolated Sb<sup>3-</sup> anions but highly disordered Zn<sup>2+</sup> cations. Dense ingots of both the α-Zn<sub>3</sub>Sb<sub>2</sub> and β-Zn<sub>13</sub>Sb<sub>10</sub> phases were formed and used to characterize and compare the low temperature thermoelectric properties. Resistivity and Seebeck coefficient measurements on α-Zn<sub>3</sub>Sb<sub>2</sub> are consistent with a small-gap, degenerately doped, p-type semiconductor. The temperature-dependent lattice thermal conductivity of α-Zn<sub>3</sub>Sb<sub>2</sub> is unusual, resembling that of an amorphous material. Consistent with the extreme degree of Zn disorder observed in the structural analysis, phonon scattering in α-Zn<sub>3</sub>Sb<sub>2</sub> appears to be completely dominated by point-defect scattering over all temperatures below 350 K. This contrasts with the typical balance between point-defect scattering and Umklapp scattering seen in β-Zn<sub>13</sub>Sb<sub>10</sub>. Using the Debye-Callaway interpretation of the lattice thermal conductivity, we use the differences between α-Zn<sub>3</sub>Sb<sub>2</sub> and β-Zn<sub>13</sub>Sb<sub>10</sub> to illustrate the potential significance of cation/anion disorder in the Zn-Sb system.</p>}},
author = {{Lo, Chun Wan Timothy and Ortiz, Brenden R. and Toberer, Eric S. and He, Allan and Svitlyk, Volodymyr and Chernyshov, Dmitry and Kolodiazhnyi, Taras and Lidin, Sven and Mozharivskyj, Yurij}},
issn = {{0897-4756}},
language = {{eng}},
month = {{06}},
number = {{12}},
pages = {{5249--5258}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Chemistry of Materials}},
title = {{Synthesis, Structure, and Thermoelectric Properties of α-Zn<sub>3</sub>Sb<sub>2</sub> and Comparison to β-Zn<sub>13</sub>Sb<sub>10</sub>}},
url = {{http://dx.doi.org/10.1021/acs.chemmater.7b01214}},
doi = {{10.1021/acs.chemmater.7b01214}},
volume = {{29}},
year = {{2017}},
}