Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub>
Thermoelectric generators are an excellent option for waste heat reuse. Materials for such devices have seen their thermoelectric properties improving constantly. The functioning of a generator, however, does not only depend on thermoelectric properties. Thermal and mechanical properties play a deci...
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MDPI AG
2022-01-01
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Online Access: | https://www.mdpi.com/1996-1944/15/3/779 |
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author | Gustavo Castillo-Hernández Eckhard Müller Johannes de Boor |
author_facet | Gustavo Castillo-Hernández Eckhard Müller Johannes de Boor |
author_sort | Gustavo Castillo-Hernández |
collection | DOAJ |
description | Thermoelectric generators are an excellent option for waste heat reuse. Materials for such devices have seen their thermoelectric properties improving constantly. The functioning of a generator, however, does not only depend on thermoelectric properties. Thermal and mechanical properties play a decisive role in the feasibility of any thermoelectric generator. To shed light on the properties exhibited by thermoelectric materials, we present the temperature dependent characterization of Young’s modulus and coefficient of thermal expansion for Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub>. Comparing undoped to Bi-doped n-type and Li-doped p-type material, we investigated the influence of doping in the relevant temperature regime and found the influences to be minor, proving similar properties for n- and p-type. We found a Young’s modulus of 84 GPa for the p-type and 83 GPa for the n-type, similar to that of the undoped compound with 85 GPa. The thermal expansion coefficients of undoped, as well as n- and p-type were equally similar with values ranging from 16.5 to 17.5 × 10<sup>−6</sup> 1/K. A phase analysis was performed to further compare the two materials, finding a similar phase distribution and microstructure. Finally, using the gathered data, estimations on the possible thermally induced stresses under a temperature difference are provided to evaluate the relevance of knowing temperature dependent thermal and mechanical properties. |
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institution | Directory Open Access Journal |
issn | 1996-1944 |
language | English |
last_indexed | 2024-03-09T23:38:03Z |
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spelling | doaj.art-856cefaa9c9c4ff794f6110804362f372023-11-23T16:57:00ZengMDPI AGMaterials1996-19442022-01-0115377910.3390/ma15030779Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub>Gustavo Castillo-Hernández0Eckhard Müller1Johannes de Boor2Institute of Materials Research, German Aerospace Center, 51170 Cologne, GermanyInstitute of Materials Research, German Aerospace Center, 51170 Cologne, GermanyInstitute of Materials Research, German Aerospace Center, 51170 Cologne, GermanyThermoelectric generators are an excellent option for waste heat reuse. Materials for such devices have seen their thermoelectric properties improving constantly. The functioning of a generator, however, does not only depend on thermoelectric properties. Thermal and mechanical properties play a decisive role in the feasibility of any thermoelectric generator. To shed light on the properties exhibited by thermoelectric materials, we present the temperature dependent characterization of Young’s modulus and coefficient of thermal expansion for Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub>. Comparing undoped to Bi-doped n-type and Li-doped p-type material, we investigated the influence of doping in the relevant temperature regime and found the influences to be minor, proving similar properties for n- and p-type. We found a Young’s modulus of 84 GPa for the p-type and 83 GPa for the n-type, similar to that of the undoped compound with 85 GPa. The thermal expansion coefficients of undoped, as well as n- and p-type were equally similar with values ranging from 16.5 to 17.5 × 10<sup>−6</sup> 1/K. A phase analysis was performed to further compare the two materials, finding a similar phase distribution and microstructure. Finally, using the gathered data, estimations on the possible thermally induced stresses under a temperature difference are provided to evaluate the relevance of knowing temperature dependent thermal and mechanical properties.https://www.mdpi.com/1996-1944/15/3/779mechanical propertiesthermoelectricMg<sub>2</sub>SiMg<sub>2</sub>Snthermal expansion |
spellingShingle | Gustavo Castillo-Hernández Eckhard Müller Johannes de Boor Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub> Materials mechanical properties thermoelectric Mg<sub>2</sub>Si Mg<sub>2</sub>Sn thermal expansion |
title | Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub> |
title_full | Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub> |
title_fullStr | Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub> |
title_full_unstemmed | Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub> |
title_short | Impact of the Dopant Species on the Thermomechanical Material Properties of Thermoelectric Mg<sub>2</sub>Si<sub>0.3</sub>Sn<sub>0.7</sub> |
title_sort | impact of the dopant species on the thermomechanical material properties of thermoelectric mg sub 2 sub si sub 0 3 sub sn sub 0 7 sub |
topic | mechanical properties thermoelectric Mg<sub>2</sub>Si Mg<sub>2</sub>Sn thermal expansion |
url | https://www.mdpi.com/1996-1944/15/3/779 |
work_keys_str_mv | AT gustavocastillohernandez impactofthedopantspeciesonthethermomechanicalmaterialpropertiesofthermoelectricmgsub2subsisub03subsnsub07sub AT eckhardmuller impactofthedopantspeciesonthethermomechanicalmaterialpropertiesofthermoelectricmgsub2subsisub03subsnsub07sub AT johannesdeboor impactofthedopantspeciesonthethermomechanicalmaterialpropertiesofthermoelectricmgsub2subsisub03subsnsub07sub |