| The magnetic moment reversal mode and the process by which it forms in magnetic materials have long been significant problems in magnetic research.The clarification of their magnetic moment flip production process and the exact management of their magnetic moment flip will become the key to the extensive use of 1D magnetic materials in the future,according to current in-depth study on 1D magnetic nanomaterials.As a result,in this paper,one-dimensional Fe,Ni,and FeNi alloy nanowire arrays were fabricated using DC and AC electrodeposition procedures based on porous anodic aluminum oxide(AAO)templates,respectively.Furthermore,transmission electron microscopy(TEM)was used to analyze the nanowire shape and chemical composition,and an X-ray diffractometer(XRD)was used to examine the crystal structure of the nanowires.The MPMS magnetic measurement equipment was used to perform macroscopic magnetic characteristics and microscopic magnetic tests of the first-order inversion curve(FORC)on nanowire samples as the study's focal point.In addition to the materials' experimental magnetic results,we employed OOMMF software to do micro-magnetic theoretical simulations of the magnetic moment flip process of the aforesaid nanowire materials and compared the results to the experimental data for analysis.The research of this paper includes the following aspects:1.Based on AAO templates,DC and AC electrodeposition were used to create Fe,Ni,and FeNi nanowire arrays of ferromagnetic metals with varying diameters.The results of X-ray diffraction tests on the samples revealed that the above samples were polycrystalline,with Fe nanowires having a body-centered cubic structure and selectively growing along the[110] crystal orientation;Ni nanowires having a face-centered cubic structure and selectively growing along the [111] crystal orientation,and the FeNi alloy nanowires prepared by AC electrodeposition having a face-centered cubic polycrystalline structure with the [111] crystal orientation.2.Cold field emission transmission electron microscopy(TEM)was used to characterize the samples' morphology,and the results showed that the nanowire diameters were consistent with the template pore diameters;energy dispersive spectroscopy(EDS)analysis of the sample composition revealed that the elements were uniformly distributed in the nanowires,providing experimental data to support the subsequent micromagnetic simulation study;microscopic crystal structure characterization of nanowires by selected area electron diffraction(SAED)showed polycrystalline structures in all samples,which is consistent with the X-ray diffraction results.3.The magnetic parameters of the prepared ferromagnetic metal nanowire arrays of various diameters were measured at room temperature using a magnetic measurement system(MPMS),and the hysteresis lines(M-H curves)revealed that the coercivity and remanence ratio of the samples decreased as the nanowire diameter increased.4.The first-order inversion curve of the microscopic magnetic variation of nanowires was also tested by MPMS based on the macroscopic magnetic test results,and the FORC contour distribution map was obtained by data processing,and the analysis was discovered that the static magnetic interaction between nanowires increased with the increase of nanowire diameter.5.The magnetic moment flip process simulation of nanowire arrays was performed using the OOMMF micromagnetic simulation software:(1)Theoretical simulations of the magnetization process of nanowires with varied aspect ratios were carried out,and the simulation findings agreed well with the experimental data;(2)the internal magnetic moment flip and distribution state of nanowires were studied by micro-magnetic slicing processing,and the magnetization behavior of the internal magnetic moment of nanowires was recorded in detail,which provides an important tool for understanding the magnetic moment flip process and formation mechanism of one-dimensional magnetic nanowires. |
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