Study of Magnetic Properties of Fe100-xNix Nanostructures Using the Mössbauer Spectroscopy Method

Abstract

Hyperfine interactions of 57Fe nuclei in Fe100-xNix nanostructures synthesized in polymer ion-track membranes were studied by Mössbauer spectroscopy. The main part of obtained nanostructures was Fe100-xNix nanotubes with bcc structure for 0 ≤ x ≤ 40, and with fcc structure for 50 ≤ x ≤ 90. The length, outside diameter and wall thickness of nanotubes were 12 μm, 400 ± 10 nm and 120 ± 5 nm respectively. For the studied nanotubes a magnetic texture is observedalong their axis. The average value of the angle between the direction of the Fe atom magnetic moment and the nanotubes axis decreases with increasing of Ni concentration for nanotubes with bcc structure from ~50° to ~40°, and with fcc structure from ~55° to ~46°. The concentration dependences of the hyperfine parameters of nanotubes Mössbauer spectra are qualitatively consistent with the data for bulk polycrystalline samples. With Ni concentration increasing the average value of the hyperfine magnetic field increases from ~328 kOe to ~335 kOe for the bcc structure and drops to ~303 kOe in the transition to the fcc structure and then decreases to ~290 kOe at x = 90. Replacing the Fe atom with the Ni atom in the nearest environment of Fe atom within nanotubes with bcc structure lead to an increase in the hyperfine magnetic field by “6–9 kOe”, and in tubes with fcc structure—to a decrease in the hyperfine magnetic field by “11–16 kOe”. The changes of the quadrupole shift and hyperfine magnetic field are linearly correlated with the coefficient −(15 ± 5)·10−4 mm/s/kOe.

The Study of the Applicability of Electron Irradiation for FeNi Microtubes Modification

“…The difference in the applied potentials for deposition was 1.75 V. As the electrolyte solution, we used iron and nickel salts-FeSO 4 × 7H 2 O, NiSO 4 × 7H 2 O in an equal molar ratio. The addition of boric (H 3 BO 3 ) and ascorbic (C 6 H 8 O 6 ) acids was used to achieve the required solution pH of 3, and also as buffer compounds to accelerate the crystallization of crystallites on the walls of tracks in polymer matrices [30,31]. To form nanostructures in the pores of the template matrices, a layer of gold 30 to 50 nm thick was deposited on one side by magnetron sputtering, which served as the cathode during deposition.…”

Impact of manganese diffusion into non-oriented electrical steel on power loss and permeability at different temperatures

“…Losses that contribute to the core loss of non-oriented electrical steels can be classified as the following: hysteresis loss, classical eddy-current loss and excess loss. It is recognised that the shape and behaviour of magnetic domains in external fields, in addition to the microstructure and texture of electrical steel, influence magnetic properties, namely hysteresis loss and excess loss (Mənescu et al, 2016;Kadyrzhanov et al, 2019;Kozlovskiy et al, 2019). One of the major contributors to total core losses is known as "eddy current losses," which are induced by electrically conductive core material, producing currents.…”

Diffusion of Alloying Cobalt Oxide (II, III) into Electrical Steel

“…The magnetic properties of electrical steel are significantly influenced by factors such as its shape, behavior, microstructure, and texture, particularly in terms of hysteresis loss and excess loss [ 10 ]. Eddy current losses, which are caused by electrically conductive core materials, make a substantial contribution to the total core losses [ 11 , 12 , 13 ]. Developing methods to enhance the core’s resistance to current flow while allowing unrestricted magnetic flux flow is essential [ 14 ].…”