Enhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave Instabilities

We investigate the layered magnetic semiconductor EuTe_{4}, focusing on its intricate charge-density-wave (CDW) states near and above room temperature through single-crystal x-ray diffraction (XRD), magnetic, and thermoelectric measurements. The XRD measurement revealed that the CDW state inducing t...

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Main Authors: Hidefumi Takahashi, Kiichiro Yoshida, Akitoshi Nakano, Shintaro Ishiwata
Format: Article
Language:English
Published: American Physical Society 2025-08-01
Series:PRX Energy
Online Access:http://doi.org/10.1103/9bvh-3r6w
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author Hidefumi Takahashi
Kiichiro Yoshida
Akitoshi Nakano
Shintaro Ishiwata
author_facet Hidefumi Takahashi
Kiichiro Yoshida
Akitoshi Nakano
Shintaro Ishiwata
author_sort Hidefumi Takahashi
collection DOAJ
description We investigate the layered magnetic semiconductor EuTe_{4}, focusing on its intricate charge-density-wave (CDW) states near and above room temperature through single-crystal x-ray diffraction (XRD), magnetic, and thermoelectric measurements. The XRD measurement revealed that the CDW state inducing the polar lattice distortion persists even at 650 K, demonstrating its remarkable thermal stability. Notably, the Seebeck coefficient near room temperature reaches values exceeding 500 µV K^{−1}. This large Seebeck coefficient, not fully captured by a simple band calculation, is comparable to those observed in heavy-electron semiconducting oxides, suggesting the importance of electron correlation and spin- and lattice instabilities. Furthermore, potentially reflecting the competition of two types of CDW state, the thermal conductivity near room temperature is as low as 0.02 W cm^{−1} K^{−1}. As a result, the thermoelectric figure of merit zT reaches 0.22 at 460 K. These findings establish EuTe_{4} as a compelling platform to explore novel types of thermoelectric materials with multiple electronic instability.
format Article
id doaj-art-65375b80a89946dca74b6229c70df739
institution Kabale University
issn 2768-5608
language English
publishDate 2025-08-01
publisher American Physical Society
record_format Article
series PRX Energy
spelling doaj-art-65375b80a89946dca74b6229c70df7392025-08-21T14:01:30ZengAmerican Physical SocietyPRX Energy2768-56082025-08-014303300910.1103/9bvh-3r6wEnhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave InstabilitiesHidefumi TakahashiKiichiro YoshidaAkitoshi NakanoShintaro IshiwataWe investigate the layered magnetic semiconductor EuTe_{4}, focusing on its intricate charge-density-wave (CDW) states near and above room temperature through single-crystal x-ray diffraction (XRD), magnetic, and thermoelectric measurements. The XRD measurement revealed that the CDW state inducing the polar lattice distortion persists even at 650 K, demonstrating its remarkable thermal stability. Notably, the Seebeck coefficient near room temperature reaches values exceeding 500 µV K^{−1}. This large Seebeck coefficient, not fully captured by a simple band calculation, is comparable to those observed in heavy-electron semiconducting oxides, suggesting the importance of electron correlation and spin- and lattice instabilities. Furthermore, potentially reflecting the competition of two types of CDW state, the thermal conductivity near room temperature is as low as 0.02 W cm^{−1} K^{−1}. As a result, the thermoelectric figure of merit zT reaches 0.22 at 460 K. These findings establish EuTe_{4} as a compelling platform to explore novel types of thermoelectric materials with multiple electronic instability.http://doi.org/10.1103/9bvh-3r6w
spellingShingle Hidefumi Takahashi
Kiichiro Yoshida
Akitoshi Nakano
Shintaro Ishiwata
Enhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave Instabilities
PRX Energy
title Enhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave Instabilities
title_full Enhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave Instabilities
title_fullStr Enhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave Instabilities
title_full_unstemmed Enhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave Instabilities
title_short Enhanced Thermopower in a Magnetic Semiconductor EuTe_{4} with Multiple Charge-Density-Wave Instabilities
title_sort enhanced thermopower in a magnetic semiconductor eute 4 with multiple charge density wave instabilities
url http://doi.org/10.1103/9bvh-3r6w
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AT kiichiroyoshida enhancedthermopowerinamagneticsemiconductoreute4withmultiplechargedensitywaveinstabilities
AT akitoshinakano enhancedthermopowerinamagneticsemiconductoreute4withmultiplechargedensitywaveinstabilities
AT shintaroishiwata enhancedthermopowerinamagneticsemiconductoreute4withmultiplechargedensitywaveinstabilities