Magnetic moment orientations in alpha-Fe nanowire arrays embedded in anodic aluminum oxide templates

Abstract

Magnetic moment orientations of α-Fe nanowire arrays with two different diameters have been investigated by means of transmission Mössbauer spectroscopy (MS) and conversion electron Mössbauer spectroscopy (CEMS). From the intensity ratio in the sextets of MS and CEMS, it is found that inside the α-Fe nanowire array (60 nm in diameter) the magnetic moments are well parallel to the nanowires, but near the extremities of the nanowires the magnetic moment orientation deviates from parallelism to the long axis of the wire. When the diameter of the α-Fe nanowires increases (300 nm in diameter), CEM spectra indicate that the mean angle of orientation between the moment direction and the long axis of the wire becomes larger near the extremities of the nanowires. The calculated configurations of magnetic moment orientations are consistent with the MS and CEMS measurements.

Morphology and magnetic behaviour of an Fe3O4nanotube array

“…From the peak area ratio, we estimated the concentration of α-Fe to be 5%. Because For one-dimensional magnetic nanowire, the demagnetization field tends to align the magnetic moments along the axis of the nanowire, which has been confirmed for Fe, FeCo alloy, and Fe oxide nanowire arrays by transmission Mössbauer spectroscopy [16]. For two- dimensional thin magnetic film, the demagnetization field tends to push down the magnetic moments in the plane.…”

Thickness dependence of the microstructures and magnetic properties of electroplated Co nanowires

“…For a long magnetic nanowire without magnetocrystalline anisotropy, the strong shape anisotropy tends to force the magnetic moment to be along the nanowire axis. Thick nanowires may form antiparallel domain structures along the nanowires and transverse domains at the ends of the nanowires [43,44]. It has been found that the nanowire length also influences the domain configuration [43,45].…”

Magnetic properties of (110)- and (200)-oriented Fe-nanowire arrays

“…One strategy is to electrodeposit magnetic nanowires into nanochannels of porous anodic aluminum oxide (AAO) templates, which have been utilized by many groups to prepare magnetic metals, such as Ni, Co, and Fe. Among earlier works, most of the Fe nanowires deposited are (1 1 0) oriented or polycrystalline [3][4][5][6][7]. It is wellknown that (1 1 0) is the hard axis of the magnetization of Fe.…”