Figure - available from: Journal of Superconductivity and Novel Magnetism
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Hysteresis loops of the multilayer thin films sputtered with different thicknesses of Al layers (┴: magnetic field perpendicular to the film plane)
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![XRD patterns of 4 [Fe(5 nm)/Al(45 nm)] multilayer thin films deposited...](profile/Hakan-Koeckar/publication/334544373/figure/fig5/AS:961851286355995@1606334625942/XRD-patterns-of-4-Fe5nm-Al45nm-multilayer-thin-films-deposited-at-the-low-and-high_Q320.jpg)
This study contains parametric characterizations of four different series of Fe/Al multilayer thin films sputtered under thicknesses of Al layers (7.5, 35 and 95 nm), deposition rates (0.02 and 0.06 nm/s), Fe layer thicknesses (7.5, 12.5 and 27.5 nm) and total thicknesses (100, 125 and 175 nm), separately. The X-ray diffraction measurements showed...
Citations
... A lot of studies were devoted, lately, to the magnetic properties of Fe as thin films or as part of multilayers. Various preparation conditions and characterization methods have been used to investigate different features and phenomena in Fe [12][13][14][15][16][17][18][19][20][21][22][23][24][25]. In a previous work, series of Fe thin films have been prepared by thermal evaporation onto glass, Si(100) and Al substrates. ...
The switching field distribution (SFD) and the loop squareness, S*, are investigated for a series of evaporated Fe thin films grown onto single crystal Si(100), polycrystalline Al and amorphous glass substrates. The SFD and S* values have been inferred from hysteresis curves. The magnetization curves were obtained by means of a Vibrating Sample Magnetometer (VSM). The Fe thickness ranges from 76 to 431 nm. We discuss the effects of the substrates, the Fe thickness and grain size, and the temperature on the SFD and the squarness S*. A strong effect of the substrate on the SFD and S* values and behaviors is observed. The lowest SFD values are found in the Fe/Si(100) while the highest are measured in Fe/glass for the same Fe thickness. The correspondence between the SFD and the (1-S*) values is investigated.
... However, roundish-shaped grains can be seen in the SEM image of the film in Fig. 3 (e). These grain shaped morphology may be caused by the relatively higher iron content of the film as indicated in many studies [31][32][33][34] and increase of Fe content under study. ...
The nanostructured materials exhibit quite different properties from their bulk counterparts. Therefore, in this
work, phase transition from a commercial austenitic AISI 202 (Bulk FeCrMn) stainless steel to martensitic ternary
FeCrMn thin films under variation of deposition rate were studied. The films were easily sputtered onto a flexible
amorphous polymer substrate from the target by a DC magnetron. X-ray diffraction analysis showed that
austenitic phase of the target converted into a mixture of martensitic and a very weak of austenitic phase of the
films at the deposition rates of 0.04 and 0.06 nm/s. With a further increase of the deposition rate, martensitic
phase in the films increased, and at the highest deposition rate, the film with 100 % martensite phase was obtained.
According to magnetic analysis, austenitic target consists of paramagnetic and ferromagnetic components
as oppose to the paramagnetic phase stated in the literature. The films obtained by sputtering of austenitic target
have ferromagnetic character with an increasing saturation magnetization, MS as the deposition rate increases.
The increase of the MS from 117 to 346 emu.cm 3 may be explained by the increase of the % martensite that may
increase the ferromagnetic character. Also, the increase of the coercivity of the films from 31 to 196 Oe may have
come from the increase of % martensite and the increase of grain sizes with increasing deposition rates which
may induce the stress in the films. It is seen that the nanostructured ternary FeCrMn thin films exhibit quite
different phase and corresponding magnetic properties from their bulk counterpart. With sputtering, martensitic
phase transition of ternary FeCrMn thin films can be controlled by varying deposition rates. It presents a potential
usage for data storage and micro electric-electronic devices on flexible substrates.
... There are many studies in which Fe is used together with Al to form different types of structures and in which their various properties are examined [11,12]. Fe/Al multilayers are an important type of these structures [13,14]. In [13], Fe/Al multilayers were produced by changing each parameter and keeping the order of the rest of the parameters constant, i.e., using the "one factor at a time" method. ...
... Fe/Al multilayers are an important type of these structures [13,14]. In [13], Fe/Al multilayers were produced by changing each parameter and keeping the order of the rest of the parameters constant, i.e., using the "one factor at a time" method. These param-eters are Al layer thicknesses (7.5, 35, and 95 nm), Al deposition rates (0.02 and 0.06 nm/s), Fe layer thicknesses (7.5, 12.5, and 27.5 nm), and total film thicknesses (100, 125, and 175 nm). ...
... It should be noted that in this study most of the deposition parameters and all values of the levels, as well as the method, are different from those used in our previous work [13]. Therefore, under the study with the Taguchi method, M s of Fe/Al MTFs was referred to, and the response and the deposition factors were analysed to obtain the improved M s value for the films. ...
Taguchi method has been conducted to improve the saturation magnetisation, Ms, of Fe/Al multilayer thin films deposited using a dual-target magnetron sputtering. The Ms values were obtained from the magnetic hysteresis loops. To evaluate the influence of deposition factors on Ms by using the Taguchi method, L9 orthogonal array with three deposition factors (A — Fe deposition rate, B — Al deposition rate, and C — Fe layer thickness) was carried out with nine experiments at three levels. For the signalto-
noise ratio of the “larger is the better”, the improved Ms has been obtained at A3B2C3, where factor A is 0.12 nm/s, factor B is 0.03 nm/s, and factor C is 25 nm. At A3B2C3, a verification experiment
was carried out with a 95% confidence level to confirm the prediction of 1597.6 emu/cm3, and in the experimental run, Ms; exp was found to be 1649.0 emu/cm3, which was an improvement from the highest initial run, i.e., Ms; ini = 1540.2 emu/cm3, among prescribed runs. Analysis of variance was imposed to obtain the F-ratio and contribution percentage of each deposition factor. Also, the interactions of the deposition factors were determined with response surface methodology. For the structural properties at the best factor combinations, X-ray diffraction experiments revealed that Fe/Al films at A3B2C3 were crystallised with the mixed phase of face-centred cubic and body-centred cubic structures. According to scanning electron microscope images, the film surface is almost uniformly shaped. Furthermore, the
model of Ms has also been developed using regression analysis as a function of the deposition factors A, B, and C. Then, from the regression model, high statistical performance was obtained, with values of R2 and R2(adj) being 100 and 100%, respectively. It is seen that the Taguchi method supported by response surface methodology, analysis of variance, and regression analysis turned out to be very successful in finding the factors with proper levels in order to improve Ms of Fe/Al multilayer thin fims within the prescribed limit.
... Magnetic multilayers and thin films exhibiting spin dependent transport phenomena such as anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), tunneling magnetoresistance (TMR), anomalous hall effect (AHE), etc., became a major field of research since the discovery of GMR in 1988 [1]. These interesting properties, exhibited by the multilayers with metallic spacer layers such as Co/Ag [2][3][4], Co/Pt [5][6][7], Ni/Ag [8], Fe/Cu [9], Fe/Al [10], etc., have been extensively studied due to their possible applications in the field of spintronics. However, apart from showing the aforementioned properties, the multilayers with metallic spacer layers have a major drawback such as shunting effect through the metallic spacer layers. ...
The influence of the Si spacer layer on the structural and magnetic properties of
Co/Si multilayers is studied. The role of disordered surface spins at the interface
of the multilayers is also studied. This study is performed by characterizing
a series of samples [Co(50 A ° )/Si(tSiA ° )]20 prepared by DC magnetron sputtering.
Structural and microstructural studies suggest that the crystallite size is
increased with decrease in the Si layer thickness. The magnetization increases
and tends to the bulk value of Co while decreasing the thickness of the Si layers.
Effect of interfacial disordered spins changes the shape of the hysteresis loop
observed in the low field regime. The disordered surface spins lead to the rise of
a crossed magnetic hysteresis loop of the multilayers.
... Fe-Al intermetallic compounds are often used as traditional engineering materials, due to their low density, high-temperature strength, outstanding oxidation and corrosion resistance. 1,2 In recent years, many studies have been made, acquiring great achievements in the application of Fe-Al as a surface protective layer, prepared with various methods. For example, T. Chrostek et al. 3 researched the functional and fractal properties of Fe-Al coatings deposited by gas-detonation spraying. ...
The static corrosion behavior of a Fe-Al layer was investigated with an immersion test in seawater, using XRD and SEM with EDS, testing the corrosion rate. The results showed that phases -Al2O3, Fe2O3 and MgO were the main corrosion products on the Fe-Al layer surface, while corrosion pits and holes were also observed. It was found that the Fe-Al layer fabricated at 750 °C exhibits a better corrosion resistance, having smaller corrosion pits and holes and also a low corrosion rate. This was related to a good formation ability of the alumina passive film.
The crystal orientation and the temperature of the substrate are crucial factors that influence clusters deposition and, consequently, the properties of thin films. In this study, the molecular dynamics simulation method was employed to investigate the deposition of Cu55 clusters on Fe(001), Fe(011), and Fe(111) substrates with varying crystal orientations. The incident energies used ranged from 0.1 to 20.0 eV/atom, and the substrates were maintained at temperatures of 300, 500, and 800 K. Analysis of cluster and substrate atom snapshots, along with the physical properties of clusters, revealed how the crystal orientation of Fe substrates affects the morphology and structure of the cluster at different temperatures. Additionally, specific microscopic mechanisms responsible for these effects were identified. The simulation results demonstrate that the crystal orientation of Fe substrate significantly influences the deposition of Cu55 clusters. The structures of the clusters on the three crystal substrates undergo similar changes as the substrate temperature increases, with the Cu55 clusters on the Fe(111) substrate exhibiting the most significant changes in response to the temperature rise.
Co/Cu films were deposited by the sputtering technique. The effects of different thicknesses of non-magnetic (Cu) layers and annealing temperature on magneto-structural properties were investigated. Different thicknesses of Cu layers were determined as 34 nm, 10 nm, 4 nm. Additionally, two annealed situations were considered to investigate the annealing effect. While the first one is exposing the films to 80 oC and 130 oC for 240 s, second one is annealing the films at 180 oC for different exposure times (50 s and 150 s). All films that have different thicknesses of Cu layers crystallized in (111) plane of the face centered cubic (fcc) structure. The intensity of this peak increased with increasing Cu layers thickness. Variation in the thickness of Cu layers has an important effect on the film surface. Saturation magnetization (Ms), coercivity (Hc) and squareness (Mr/Ms, Mr: remanent magnetization) were considerably affected by variation of the Cu content and film surface caused by the change in the thickness of the Cu layers. The film with 4 nm Cu layer thickness has the highest Ms, lowest Hc values and high Mr/Ms ratio. This indicates magnetically high efficient compared to the other films in the same series. The fcc structure continued to exist for the films annealed at 80 oC and 130 oC for 240 s. It was found that the annealing procedure transfigured the film surface and the differences in Ms and Hc values can be mostly attributed to this transfiguration because of the same film content revealed. An increase in Ms value, and a slight decrease in Hc and Mr/Ms values were detected for the annealed film at 130 oC, compared to the film annealed at 80 oC. It was also seen that the film structure was damaged at 180 oC because of excessive heat transfer.
The magnetic anisotropy is investigated for a series of Fe films prepared by electrodeposition onto porous and nonporous Al substrates and with iron chloride (FeCl
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) and iron sulfate (FeSO
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) baths. The magnetic anisotropy, inferred from hysteresis curves, is uniaxial in nature with constants
$K_{1}$
and
$K_{2}$
. We discuss the variation of these anisotropy constants as a function of the film thickness, the temperature, the Al porosity, and the bath. All samples show an in-plane magnetic anisotropy but with different strength. Depending on the preparation condition, we find a relation between the magnetic anisotropy and the out-of-plane strain, measured by X-ray diffraction (XRD), indicating that part of the magnetic anisotropy can be attributed to stress in the films.
