Thermopile based on anisotropic magneto-Peltier effect

First-principles study of the anisotropic magneto-Peltier effect

We study theoretically the anisotropic magneto-Peltier effect, which was recently demonstrated experimentally. A first-principles-based Boltzmann transport approach including the spin-orbit interaction shows that Ni has a larger anisotropy of the Peltier coefficient ($ΔΠ$) than Fe, consistent with experiments. It is clarified that spin-flip electron transitions due to the spin-orbit interaction are the key in the mechanism of the large anisotropic magneto-Peltier effect. Using our method, we further predict several ferromagnetic metals with much larger $ΔΠ$ than that of Ni.

Comparison of the magneto-Peltier and magneto-Seebeck effects in magnetic tunnel junctions

Understanding heat generation and transport processes in a magnetic tunnel junction (MTJ) is a significant step towards improving its application in current memory devices. Recent work has experimentally demonstrated the magneto-Seebeck effect in MTJs, where the Seebeck coefficient of the junction varies as the magnetic configuration changes from a parallel (P) to an anti-parallel (AP) configuration. Here we report the study on its as-yet-unexplored reciprocal effect, the magneto-Peltier effect, where the heat flow carried by the tunneling electrons is altered by changing the magnetic configur…

Systematic Investigation of Anisotropic Magneto-Peltier Effect and Anomalous Ettingshausen Effect in Ni Thin Films

The anisotropic magneto-Peltier effect (AMPE) and anomalous Ettingshausen effect (AEE) have been investigated in U-shaped Ni thin films of varying thickness and substrate by means of the lock-in thermography (LIT) method. We have established a procedure to extract pure AMPE and AEE contributions, separated from other thermoelectric effects, for ferromagnetic thin films. The measurements of the magnetic-field-angle $θ_{\rm H}$ dependence of the LIT images clearly show that the temperature modulation induced by the AMPE (AEE) in the Ni films varies with the $\cos 2θ_{\rm H}$ ($\cos θ_{\rm H}$) p…

High-throughput imaging measurements of thermoelectric figure of merit

We demonstrate a method for the simultaneous determination of the thermoelectric figure of merit of multiple martials by means of the lock-in thermography (LIT) technique. This method is based on the thermal analyses of the transient temperature distribution induced by the Peltier effect and Joule heating, which enables high-throughput estimation of the thermal diffusivity, thermal conductivity, volumetric heat capacity, Seebeck or Peltier coefficient of the materials. The LIT-based approach has high reproducibility and reliability because it offers sensitive noncontact temperature measurement…

具有高度非平衡磁振子的绝缘体上金属中依赖频率的声子介导单向磁阻

Frequency-dependent Phonon-mediated Unidirectional Magnetoresistance in a Metal on an Insulator with Highly Nonequilibrium Magnons

本研究针对重金属/磁性绝缘体双层结构，提出考虑自旋珀尔帖效应、电子-声子散射及磁振子局域非平衡的解析模型，解释了单向磁阻与自旋塞贝克效应的频率依赖性，揭示了热穿透深度与磁振子自旋扩散长度的关联机制。

Spin-mediated charge-to-heat current conversion phenomena in ferromagnetic binary alloys

Spin-mediated charge-to-heat current conversion phenomena, i.e., the anomalous Ettingshausen effect (AEE) and the anisotropic magneto-Peltier effect (AMPE), have been investigated in various ferromagnetic Ni-Fe, Ni-Pt, Ni-Pd, and Fe-Pt binary alloys at room temperature. When a charge current is applied to a ferromagnetic conductor, the AMPE modulates the Peltier coefficient depending on the angle between the directions of the charge current and magnetization, while the AEE generates a heat current in the direction perpendicular to both the charge current and magnetization. We observed the stro…