Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03)
A thermoelectric generator, as a solid-state device, is considered a potential candidate for recovering waste heat directly as electrical energy without any moving parts. However, thermoelectric materials limit the application of thermoelectric devices due to their high costs. Therefore, in this wor...
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MDPI AG
2023-01-01
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| Online Access: | https://www.mdpi.com/1996-1944/16/3/927 |
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| author | Sopheap Sam Soma Odagawa Hiroshi Nakatsugawa Yoichi Okamoto |
| author_facet | Sopheap Sam Soma Odagawa Hiroshi Nakatsugawa Yoichi Okamoto |
| author_sort | Sopheap Sam |
| collection | DOAJ |
| description | A thermoelectric generator, as a solid-state device, is considered a potential candidate for recovering waste heat directly as electrical energy without any moving parts. However, thermoelectric materials limit the application of thermoelectric devices due to their high costs. Therefore, in this work, we attempt to improve the thermoelectric properties of a low-cost material, iron silicide, by optimizing the Ni doping level. The influence of Ni substitution on the structure and electrical and thermoelectric characteristics of bulk <i>β</i>-Fe<sub>x</sub>Ni<sub>1−x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) prepared by the conventional arc-melting method is investigated. The thermoelectric properties are reported over the temperature range of 80–800 K. At high temperatures, the Seebeck coefficients of Ni-substituted materials are higher and more uniform than that of the pristine material as a result of the reduced bipolar effect. The electrical resistivity decreases with increasing x owing to the increases in metallic ε-phase and carrier density. The ε-phase increases with Ni substitution, and solid solution limits of Ni in <i>β</i>-FeSi<sub>2</sub> can be lower than 1%. The highest power factor of 200 μWm<sup>−1</sup>K<sup>−2</sup> at 600 K is obtained for x = 0.001, resulting in the enhanced <i>ZT</i> value of 0.019 at 600 K. |
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| id | doaj.art-ad1de2bd5f134b89b6f9c917681ae407 |
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| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T09:36:48Z |
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| spelling | doaj.art-ad1de2bd5f134b89b6f9c917681ae4072023-11-16T17:14:38ZengMDPI AGMaterials1996-19442023-01-0116392710.3390/ma16030927Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03)Sopheap Sam0Soma Odagawa1Hiroshi Nakatsugawa2Yoichi Okamoto3Yokohama National University, Yokohama 240-8501, JapanYokohama National University, Yokohama 240-8501, JapanYokohama National University, Yokohama 240-8501, JapanNational Defense Academy, Yokosuka 239-8686, JapanA thermoelectric generator, as a solid-state device, is considered a potential candidate for recovering waste heat directly as electrical energy without any moving parts. However, thermoelectric materials limit the application of thermoelectric devices due to their high costs. Therefore, in this work, we attempt to improve the thermoelectric properties of a low-cost material, iron silicide, by optimizing the Ni doping level. The influence of Ni substitution on the structure and electrical and thermoelectric characteristics of bulk <i>β</i>-Fe<sub>x</sub>Ni<sub>1−x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) prepared by the conventional arc-melting method is investigated. The thermoelectric properties are reported over the temperature range of 80–800 K. At high temperatures, the Seebeck coefficients of Ni-substituted materials are higher and more uniform than that of the pristine material as a result of the reduced bipolar effect. The electrical resistivity decreases with increasing x owing to the increases in metallic ε-phase and carrier density. The ε-phase increases with Ni substitution, and solid solution limits of Ni in <i>β</i>-FeSi<sub>2</sub> can be lower than 1%. The highest power factor of 200 μWm<sup>−1</sup>K<sup>−2</sup> at 600 K is obtained for x = 0.001, resulting in the enhanced <i>ZT</i> value of 0.019 at 600 K.https://www.mdpi.com/1996-1944/16/3/927iron silicidebipolar effectNi dopingthermoelectric properties<i>ZT</i> values |
| spellingShingle | Sopheap Sam Soma Odagawa Hiroshi Nakatsugawa Yoichi Okamoto Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) Materials iron silicide bipolar effect Ni doping thermoelectric properties <i>ZT</i> values |
| title | Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) |
| title_full | Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) |
| title_fullStr | Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) |
| title_full_unstemmed | Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) |
| title_short | Effect of Ni Substitution on Thermoelectric Properties of Bulk <i>β</i>-Fe<sub>1−x</sub>Ni<sub>x</sub>Si<sub>2</sub> (0 ≤ x ≤ 0.03) |
| title_sort | effect of ni substitution on thermoelectric properties of bulk i β i fe sub 1 x sub ni sub x sub si sub 2 sub 0 ≤ x ≤ 0 03 |
| topic | iron silicide bipolar effect Ni doping thermoelectric properties <i>ZT</i> values |
| url | https://www.mdpi.com/1996-1944/16/3/927 |
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