Sola A, Bougiatioti P, Kuepferling M, Meier D, Reiss G, Pasquale M, Kuschel T, Basso V
Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135, Turin, Italy.
Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitatsstrasse 25, 33615 Bielefeld, Germany.
Sci Rep. 2017 Apr 25;7:46752. doi: 10.1038/srep46752.
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 Vm/W and (1.101 ± 0.015) 10 Vm/W with the heat flux method and (2.313 ± 0.017) 10 V/K and (4.956 ± 0.005) 10 V/K with the temperature difference method. This shows that systematic errors can be considerably reduced with the heat flux method.
纵向自旋塞贝克效应（LSSE）系数的测定目前因测量中所用实验条件的可重复性差而存在很大的不确定性。在这项工作中，我们对用于测定LSSE系数的两种不同方法进行了详细分析。我们在不同实验室进行了LSSE实验，使用了不同的装置，并采用了温差法和热流法。我们发现，缺乏可重复性主要可归因于产生温度梯度的样品与热浴之间的热接触电阻。由于热阻的变化，我们发现将LSSE电压按通过样品的热流而非样品两端的温差进行缩放可大大降低不确定性。用两种不同装置获得的单个YIG/Pt LSSE器件的特性，热流法得到的结果为(1.143±0.007)×10 Vm/W和(1.101±0.015)×10 Vm/W，温差法得到的结果为(2.313±0.017)×10 V/K和(4.956±0.005)×10 V/K。这表明热流法可大幅降低系统误差。
