Zhang Junwei, Peng Yong, Ma Hongbin, Zhang Senfu, Hu Yang, Zeng Xue, Deng Xia, Guan Chaoshuai, Chen Rongrong, Hu Yue, Karim Abdul, Tao Kun, Zhang Mingjie, Zhang Xixiang
Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou 730000, P. R. China.
Qinghai Provincial Key Laboratory of New Light Alloys, Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and Forming, Qinghai University, Xining 810016, PR China.
ACS Appl Mater Interfaces. 2020 Sep 2;12(35):39798-39806. doi: 10.1021/acsami.0c09773. Epub 2020 Aug 24.
The accurate magnetoresistance (MR) measurement of individual nanostructures is essential and important for either the enrichment of fundamental knowledge of the magnetotransport mechanism or the facilitation of desired design of magnetic nanostructures for various technological applications. Herein, we report a deep investigation on the magnetotransport mechanism of a single CoCu/Cu multilayered nanowire direct MR measurement using our invented magnetotransport instrument scanning electron microscope. Off-axis electron holography experiments united with micromagnetic simulation prove that the CoCu layers in CoCu/Cu multilayered nanowires form a single-domain structure, in which the alignment of magnetic moments is mainly determined by shape anisotropy. The MR of the single CoCu/Cu multilayered nanowire is measured to be only 1.14% when the varied external field is applied along the nanowire length axis, which matches with the theoretical prediction of the granular film model. Density functional theory calculations further disclose that spin-dependent scattering at the interface between magnetic and nonmagnetic layers is responsible for the intrinsic magnetotransport mechanism.
对单个纳米结构进行精确的磁电阻（MR）测量，对于丰富磁输运机制的基础知识或推动用于各种技术应用的磁性纳米结构的理想设计而言至关重要。在此，我们报告了一项对单个CoCu/Cu多层纳米线磁输运机制的深入研究，使用我们发明的磁输运仪器——扫描电子显微镜进行直接MR测量。离轴电子全息实验与微磁模拟相结合证明，CoCu/Cu多层纳米线中的CoCu层形成单畴结构，其中磁矩的排列主要由形状各向异性决定。当沿纳米线长度轴施加变化的外部磁场时，单个CoCu/Cu多层纳米线的MR测量值仅为1.14%，这与颗粒膜模型的理论预测相符。密度泛函理论计算进一步揭示，磁性和非磁性层之间界面处的自旋相关散射是本征磁输运机制的原因。
