Magnetotransport Mechanism of Individual Nanostructures via Direct Magnetoresistance Measurement in situ SEM

Abstract

The accurate magnetoresistance (MR) measurement of individual nanostructures is essential and important for either the enrichment of fundamental knowledge of magneto-transport mechanism or the facilitation of desired design of magnetic nanostructures for various technological applications. Herein, we report a deep investigation on the magneto-transport mechanism of single CoCu/Cu multilayered nanowire via direct magnetoresistance measurement by using our invented magneto-transport instrument in-situ scanning electron microscope (SEM). Off-axis electron holography experiments united with micromagnetic simulation prove that the CoCu layers in CoCu/Cu multilayered nanowires are formed 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 nanowire length axis, which matches with the theoretical prediction of Granular Films model. Density functional theory (DFT) calculations further disclose that spin-dependent scattering at the interface between magnetic and nonmagnetic layers is responsible for the intrinsic magneto-transport mechanism.