Exploiting bi-modulated magnetic field and drive current modulation to achieve high-sensitivity Hall measurements on thermoelectric samples
Exploiting bi-modulated magnetic field and drive current modulation to achieve high-sensitivity Hall measurements on thermoelectric samples
复制标题
利用双调制磁场和驱动电流调制实现热电样品的高灵敏度霍尔测量
DOI：
10.1557/s43580-022-00258-7
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发表时间：
2022
期刊：
影响因子：
0.8
通讯作者：
M. Togay
中科院分区：
文献类型：
--
作者：
G. Paráda;F. Korsós;A. Bojtor;J. Bos;E. Don;J. Bowers;M. Togay
由于低霍尔电压，具有高载流子密度的样品的霍尔迁移率测量具有挑战性。增加驱动电流会提高霍尔电压，但会导致触点处的焦耳加热风险，从而导致不可靠的测量。测量噪声抑制可以通过在霍尔测量期间调制磁场或驱动电流来实现。平行偶极子线（PDL）交流霍尔测量技术是一种非常实用的方法，可以使用旋转永磁体在非常紧凑的设计中实现纯谐波磁场调制。在这项工作中，我们将联合收割机磁场调制与交变极性驱动电流相结合，即，在非常不同的频率下使用同时的双参数调制以获得进一步的噪声降低。它可以确定具有非常高的自由载流子密度（超过1 E21 cm^-3）的材料中的载流子迁移率。在掺锡NbCoSb热电样品上测试了双调制方法的可靠性和适用性。结果显示出对样品的化学组成的优异的灵敏度，因此被证明是开发此类材料的有效方法。图形摘要
Hall mobility measurements of samples with high carrier density are challenging due to the low Hall voltage. Increasing the drive current enhances the Hall voltage, but risks Joule heating at the contacts resulting in unreliable measurements. Measurement noise suppression can be achieved by modulating either the magnetic field or the drive current during the Hall measurement. The Parallel dipole line (PDL) AC Hall measurement technique is a very practical way to realize pure harmonic magnetic field modulation in a very compact design using rotating permanent magnets. In this work, we combine magnetic field modulation with alternating polarity drive current, i.e., using a simultaneous two-parameter modulation at very different frequencies to gain further noise reduction. It makes possible to determine the charge carrier mobility in materials featuring very high free carrier density (over 1 E21 cm^−3). The reliability and the applicability of the bi-modulation method was tested on Sn doped NbCoSb thermoelectric samples. The results exhibited excellent sensitivity to the chemical composition of the samples and therefore proven to be an efficient method for the development of such materials. Graphical abstract
影响因子：
29.4
作者：
Snyder, G. Jeffrey;Snyder, Alemayouh H.;Niu, Changning
通讯作者：
Niu, Changning