Time-resolved measurement of the tunnel magneto-Seebeck effect in a single magnetic tunnel junction
Time-resolved measurement of the tunnel magneto-Seebeck effect in a single magnetic tunnel junction
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DOI：
10.1063/1.4811130
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发表时间：
2013-06-01
影响因子：
1.6
通讯作者：
Reiss, Guenter
中科院分区：
文献类型：
--
作者：
Boehnke, Alexander;Walter, Marvin;Reiss, Guenter
最近，一些研究小组报道了磁隧道结中自旋相关的热电效应。在本文中，我们提出了一个时间分辨测量的热电压和热流的一个单一的微米到纳米尺度的隧道结的设置。电调制二极管激光器用于在隧道结层堆叠上产生温度梯度。这种激光调制技术能够记录时间依赖性的热电压信号，其时间分辨率仅受热电压的时间分辨率的限制。到目前为止，时间依赖的热电压无法解释。现在，与本文中提出的设置，它是可能的，以区分不同的塞贝克电压的贡献，总的测量电压信号在μ s的时间制度。开发了一个模型电路，解释了不同样品类型的电压贡献。此外，它将被示出，从磁隧道结产生的电压信号只能被观察到当激光点直接集中在顶部的磁隧道结，这允许横向分离的效果。(C)2013 AIP Publishing LLC.
Recently, several groups have reported spin-dependent thermoelectric effects in magnetic tunnel junctions. In this paper, we present a setup for time-resolved measurements of thermovoltages and thermocurrents of a single micro-to nanometer-scaled tunnel junction. An electrically modulated diode laser is used to create a temperature gradient across the tunnel junction layer stack. This laser modulation technique enables the recording of time-dependent thermovoltage signals with a temporal resolution only limited by the preamplifier for the thermovoltage. So far, time-dependent thermovoltage could not be interpreted. Now, with the setup presented in this paper, it is possible to distinguish different Seebeck voltage contributions to the overall measured voltage signal in the mu s time regime. A model circuit is developed that explains those voltage contributions on different sample types. Further, it will be shown that a voltage signal arising from the magnetic tunnel junction can only be observed when the laser spot is directly centered on top of the magnetic tunnel junction, which allows a lateral separation of the effects. (C) 2013 AIP Publishing LLC.