Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique
The Seebeck coefficient is the most widely measured property specific to thermoelectric materials. The absolute Seebeck coefficient S determined from the Thomson effect is highly sensitive to systematic errors incurred in the determination of the material thermal conductivity and geometry and heat l...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2019-06-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/1.5095485 |
| _version_ | 1819261259748474880 |
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| author | Y. Amagai T. Shimazaki K. Okawa H. Fujiki T. Kawae N.-H. Kaneko |
| author_facet | Y. Amagai T. Shimazaki K. Okawa H. Fujiki T. Kawae N.-H. Kaneko |
| author_sort | Y. Amagai |
| collection | DOAJ |
| description | The Seebeck coefficient is the most widely measured property specific to thermoelectric materials. The absolute Seebeck coefficient S determined from the Thomson effect is highly sensitive to systematic errors incurred in the determination of the material thermal conductivity and geometry and heat loss from the sample to surroundings caused by temperature differences. Here, we report a technique for the precision measurement of S based on the Thomson effect using an ac-dc technique. This technique utilizes accurate equivalent-amplitude ac and dc currents, which can eliminate the need for acquiring accurate thermal conductivity and geometry values. These parameters can be replaced by the precisely and readily measurable parameters of electrical resistance and temperature changes caused by the Joule effect. The correction term of the heat loss owing to heat transfer via the thermocouple vanishes upon calculating the ratio of the measured temperature changes for both ac and dc excitations. We obtain an S value of -4.8 μV/K ± 0.2 μV/K at a temperature of 300 K for platinum, which is most widely used as a reference, with an expanded relative uncertainty of 4% (2σ). The obtained S value of Pt is closely consistent with that obtained from the conventional method using the Thomson effect within the uncertainty, and importantly, the measurement uncertainty improves to an acceptable level, which is four times more precise. |
| first_indexed | 2024-12-23T19:38:58Z |
| format | Article |
| id | doaj.art-a425faef771840cf801aba59d6974341 |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-12-23T19:38:58Z |
| publishDate | 2019-06-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-a425faef771840cf801aba59d69743412022-12-21T17:33:43ZengAIP Publishing LLCAIP Advances2158-32262019-06-0196065312065312-610.1063/1.5095485044906ADVPrecise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc techniqueY. Amagai0T. Shimazaki1K. Okawa2H. Fujiki3T. Kawae4N.-H. Kaneko5National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ), Tsukuba 305-8563, JapanNational Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ), Tsukuba 305-8563, JapanNational Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ), Tsukuba 305-8563, JapanNational Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ), Tsukuba 305-8563, JapanKyushu University Department of Applied Quantum Physics, Fukuoka 819-0395, JapanNational Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ), Tsukuba 305-8563, JapanThe Seebeck coefficient is the most widely measured property specific to thermoelectric materials. The absolute Seebeck coefficient S determined from the Thomson effect is highly sensitive to systematic errors incurred in the determination of the material thermal conductivity and geometry and heat loss from the sample to surroundings caused by temperature differences. Here, we report a technique for the precision measurement of S based on the Thomson effect using an ac-dc technique. This technique utilizes accurate equivalent-amplitude ac and dc currents, which can eliminate the need for acquiring accurate thermal conductivity and geometry values. These parameters can be replaced by the precisely and readily measurable parameters of electrical resistance and temperature changes caused by the Joule effect. The correction term of the heat loss owing to heat transfer via the thermocouple vanishes upon calculating the ratio of the measured temperature changes for both ac and dc excitations. We obtain an S value of -4.8 μV/K ± 0.2 μV/K at a temperature of 300 K for platinum, which is most widely used as a reference, with an expanded relative uncertainty of 4% (2σ). The obtained S value of Pt is closely consistent with that obtained from the conventional method using the Thomson effect within the uncertainty, and importantly, the measurement uncertainty improves to an acceptable level, which is four times more precise.http://dx.doi.org/10.1063/1.5095485 |
| spellingShingle | Y. Amagai T. Shimazaki K. Okawa H. Fujiki T. Kawae N.-H. Kaneko Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique AIP Advances |
| title | Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique |
| title_full | Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique |
| title_fullStr | Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique |
| title_full_unstemmed | Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique |
| title_short | Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique |
| title_sort | precise measurement of absolute seebeck coefficient from thomson effect using ac dc technique |
| url | http://dx.doi.org/10.1063/1.5095485 |
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