포논 부조화도 제어를 통한 고효율 스핀 열전 디바이스 제작
- Title
- 포논 부조화도 제어를 통한 고효율 스핀 열전 디바이스 제작
- Authors
- PARK, SANGJUN; JIN, HYUNGYU
- Date Issued
- 2023-04-06
- Publisher
- 한국열물성학회
- Abstract
- The spin Seebeck effect (SSE) refers to a heat-to-electricity conversion via thermal spin current (or thermal magnon) in a ferromagnet (FM)/normal metal (NM) heterostructure1. As SSE-based thermoelectric (TE) devices offer various advantages due to their transverse geometry2, where the output electrical charge is perpendicular to input heat, they do not require n- and p-type materials pairs. This enables a much simplified device structure compared to conventional Seebeck-based TE devices.
Despite their advantages, practical energy harvesting applications of SSE-based devices are challenging due to their low conversion efficiency . The efficiency of SSE is determined by the spin TE figure-of-merit zSSET=SSSE2T/FM, where SSSE is the spin Seebeck coefficient, is the electrical conductivity of NM, FM is the thermal conductivity of FM, and T is the absolute temperature. Therefore, both a high SSSE and FM could lead to a high zSSET. Previous studies have focused on increasing SSSE by improving the interface quality at FM/NM3 or by introducing a normal metal with high spin-to-charge conversion efficiency4. However, little attention has been payed to decreasing FM, as it is strongly entangled with SSSE and is hard to be controlled alone5.
Here, we report the enhanced SSE in a multiple-elements-doped iron garnet system (Fig. 1, the SSE performance is evaluated by SSR=SSSE/FM). We propose an explanation for the enhanced signal, which involves the contribution of orbital angular momentum6 on SSSE and increased phonon anharmonicity leading to a decrease in FM7.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/122074
- Article Type
- Conference
- Citation
- 제23회 한국열물성학회 학술대회, 2023-04-06
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