Longitudinal spin Seebeck coefficient: heat flux vs. temperature difference method.
Longitudinal spin Seebeck coefficient: heat flux vs. temperature difference method.
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DOI：
10.1038/srep46752
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发表时间：
2017-04-25
影响因子：
4.6
通讯作者：
Basso V
中科院分区：
文献类型：
--
作者：
Sola A;Bougiatioti P;Kuepferling M;Meier D;Reiss G;Pasquale M;Kuschel T;Basso V
由于纵向自旋塞贝克效应(LSSE)系数测量的实验条件重复性较差，目前LSSE系数的测定存在很大的不确定度。在这项工作中，我们对两种不同的确定LSSE系数的方法进行了详细的分析。我们在不同的实验室进行了LSSE实验，使用了不同的装置，并同时使用了温差法和热流法。我们发现，重复性差的主要原因是样品与热浴之间的接触热阻产生了温度梯度。由于热阻的变化，我们发现LSSE电压与通过样品的热通量而不是样品之间的温差的比例关系大大减少了不确定度。用热流法和温差法分别得到了(1.143 ± 0.007)10−7 Vm/W和(1.101 ± 0.015)10−7 Vm/W和(2.313 ± 0.017)10−7 V/K和(4.956 ± 0.005)10−7 V/K。这表明，用热流法可以大大减小系统误差。
The determination of the longitudinal spin Seebeck effect (LSSE) coefficient is currently plagued by a large uncertainty due to the poor reproducibility of the experimental conditions used in its measurement. In this work we present a detailed analysis of two different methods used for the determination of the LSSE coefficient. We have performed LSSE experiments in different laboratories, by using different setups and employing both the temperature difference method and the heat flux method. We found that the lack of reproducibility can be mainly attributed to the thermal contact resistance between the sample and the thermal baths which generate the temperature gradient. Due to the variation of the thermal resistance, we found that the scaling of the LSSE voltage to the heat flux through the sample rather than to the temperature difference across the sample greatly reduces the uncertainty. The characteristics of a single YIG/Pt LSSE device obtained with two different setups was (1.143 ± 0.007) 10−7 Vm/W and (1.101 ± 0.015) 10−7 Vm/W with the heat flux method and (2.313 ± 0.017) 10−7 V/K and (4.956 ± 0.005) 10−7 V/K with the temperature difference method. This shows that systematic errors can be considerably reduced with the heat flux method.