Comparison of the magneto-Peltier and magneto-Seebeck effects in magnetic tunnel junctions
Comparison of the magneto-Peltier and magneto-Seebeck effects in magnetic tunnel junctions
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DOI：
10.1103/physrevb.92.020414
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发表时间：
2015-05
影响因子：
3.7
通讯作者：
J. Shan;F. Dejene;J. Leutenantsmeyer;J. Flipse;M. Munzenberg;B. Wees
中科院分区：
文献类型：
--
作者：
J. Shan;F. Dejene;J. Leutenantsmeyer;J. Flipse;M. Munzenberg;B. Wees
了解磁隧道结（MTJ）中的热产生和输运过程是改善其在当前存储器件中的应用的重要一步。最近的工作已经通过实验证明了MTJs中的磁-塞贝克效应，其中结的塞贝克系数随着磁结构从平行(P)到反平行（AP）结构的变化而变化。在这里，我们报告了一项关于其互反效应的研究，即磁-珀尔帖效应，其中隧道电子携带的热流通过改变MTJ的磁构型而改变。在小偏压下，反映P和AP结构之间结的温差变化的磁-珀耳捷信号与施加电流呈线性关系，但在大偏压下，由于高阶焦耳加热机制，该信号大大增强。通过仔细提取反映磁-珀耳帖效应的线性响应，并将其与在同一设备上进行的磁-塞贝克测量进行比较，我们观察到与Onsager互易一致的结果。我们使用三维热电模型估计线性区域的磁-珀尔帖系数为13.4 mV。我们的研究结果开启了基于MTJs中的Peltier效应的可编程热电器件的可能性。
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 antiparallel (AP) configuration. Here we report a study on its reciprocal effect, the magneto-Peltier effect, where the heat flow carried by the tunneling electrons is altered by changing the magnetic configuration of the MTJ. The magneto-Peltier signal that reflects the change in the temperature difference across the junction between the P and AP configurations scales linearly with the applied current in the small bias but is greatly enhanced in the large-bias regime, due to higher-order Joule heating mechanisms. By carefully extracting the linear response which reflects the magneto-Peltier effect, and comparing it with the magneto-Seebeck measurements performed on the same device, we observe results consistent with Onsager reciprocity. We estimate a magneto-Peltier coefficient of 13.4 mV in the linear regime using a three-dimensional thermoelectric model. Our result opens up the possibility of programmable thermoelectric devices based on the Peltier effect in MTJs.