Observation of anisotropic magneto-Peltier effect in nickel
Observation of anisotropic magneto-Peltier effect in nickel
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DOI：
10.1038/s41586-018-0143-x
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发表时间：
2018-05
期刊：
影响因子：
64.8
通讯作者：
K. Uchida;S. Daimon;R. Iguchi;E. Saitoh
中科院分区：
文献类型：
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作者：
K. Uchida;S. Daimon;R. Iguchi;E. Saitoh
1834年发现的珀耳帖效应将充电电流转换为导体中的热流，其性能由珀耳帖系数描述，珀耳帖系数定义为产生的热流与施加的充电电流之比。为了利用珀耳帖效应用于热电冷却或加热，具有不同珀耳帖系数的两个导体的结被认为是必不可少的。在这里，我们通过在没有结的单一材料中演示Peltier冷却和加热来挑战这种传统智慧。这是通过各向异性磁珀耳帖效应实现的，其中珀耳帖系数取决于铁磁体中的充电电流和磁化方向之间的角度。利用主动热像技术，我们发现，可以简单地通过改变充电电流和磁化的配置，例如，通过塑造铁磁体，使电流必须围绕曲线流动，重新设计铁磁体的热电性能。我们的实验结果表明，镍的各向异性磁珀耳帖效应和自旋轨道相互作用的重要性，在其机制的适用性。这里观察到的各向异性磁珀耳帖效应是铁磁材料中缺失的热电现象-以前在铁磁体中观察到的各向异性磁塞贝克效应的Onsager倒数-并且其简单性可能在开发电子和自旋电子器件的热管理技术中证明是有用的。
The Peltier effect, discovered in 1834, converts a charge current into a heat current in a conductor, and its performance is described by the Peltier coefficient, which is defined as the ratio of the generated heat current to the applied charge current,. To exploit the Peltier effect for thermoelectric cooling or heating, junctions of two conductors with different Peltier coefficients have been believed to be indispensable. Here we challenge this conventional wisdom by demonstrating Peltier cooling and heating in a single material without junctions. This is realized through an anisotropic magneto-Peltier effect in which the Peltier coefficient depends on the angle between the directions of a charge current and magnetization in a ferromagnet. By using active thermography techniques, , , , , , –, we observe the temperature change induced by this effect in a plain nickel slab. We find that the thermoelectric properties of the ferromagnet can be redesigned simply by changing the configurations of the charge current and magnetization, for instance, by shaping the ferromagnet so that the current must flow around a curve. Our experimental results demonstrate the suitability of nickel for the anisotropic magneto-Peltier effect and the importance of spin–orbit interaction in its mechanism. The anisotropic magneto-Peltier effect observed here is the missing thermoelectric phenomenon in ferromagnetic materials—the Onsager reciprocal of the anisotropic magneto-Seebeck effect previously observed in ferromagnets—and its simplicity might prove useful in developing thermal management technologies for electronic and spintronic devices.