scholarly journals Влияние толщины слоев гадолиния на магнитные свойства и процессы перемагничивания низкоразмерных Co/Gd/Co-систем

2019 ◽  
Vol 61 (3) ◽  
pp. 460
Author(s):  
А.М. Харламова ◽  
А.В. Свалов ◽  
В.Н. Лепаловский ◽  
Е.Е. Шалыгина
Keyword(s):  
Hysteresis Loops ◽  
Nanocrystalline Structure ◽  
Magnetic Characteristics ◽  
Saturation Field ◽  
X Ray ◽  
Plasma Sputtering ◽  
Ion Plasma ◽  
Oscillatory Character ◽  
The Mean ◽  
And Behavior

AbstractStructural and magnetic characteristics and behavior of thin-film Co/Gd/Co systems obtained by ion plasma sputtering in a magnetic field are reported. X-ray studies showed that cobalt layers in all investigated samples have a nanocrystalline structure. The mean roughness R a of the surface of the samples does not exceed 0.5 nm and is independent of the Gd layer thickness. The shape of hysteresis loops observed for the Co/Gd/Co system depends of the thickness of the Gd layer, t _Gd. The dependence of the saturation field H _S on t _Gd has an oscillatory character. This fact is explained by interaction of the Co layers through the intermediate Gd layer.

scholarly journals Effect of the electrodeposition potential on the magnetic properties of FeCoNi films

2019 ◽  
Vol 37 (3) ◽  
pp. 389-394
Author(s):  
Setia Budi ◽  
Sukro Muhab ◽  
Agung Purwanto ◽  
Budhy Kurniawan ◽  
Azwar Manaf
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Sulfate Solution ◽  
Synthesis Process ◽  
Magnetic Characteristics ◽  
Soft Magnetic ◽  
X Ray ◽  
Ni Content ◽  
The Mean ◽  
Feconi Alloy

AbstractThe effect of electrodeposition potential on the magnetic properties of the FeCoNi films has been reported in this paper. The FeCoNi electrodeposition was carried out from sulfate solution using potentiostatic technique. The obtained FeCoNi films were characterized by X-ray diffractometer (XRD), atomic absorption spectrometer (AAS) and vibrating sample magnetometer (VSM). It has been shown that the electrodeposition potential applied during the synthesis process determines the magnetic characteristics of FeCoNi films. The more negative potential is applied, the higher Ni content is in the FeCoNi alloy. At the same time, Co and Fe showed almost similar trend in which the content decreased with an increase in applied potential. The mean crystallite size of FeCoNi films was ranging from 11 nm to 15 nm. VSM evaluation indicated that the FeCoNi film is a ferromagnetic alloy with magnetic anisotropy. The high saturation magnetization of FeCoNi film was ranging from 86 A·m2/kg to 105 A·m2/kg. The film is a soft magnetic material which was revealed by a very low coercivity value in the range of 1.3 kA/m to 3.7 kA/m. Both the saturation magnetization and coercivity values decreased at a more negative electrodeposition potential.

scholarly journals Structural and magnetic characteristics of the Co/Cu/Co thin-film systems

2018 ◽  
Vol 185 ◽  
pp. 03009
Author(s):  
Elena Shalygina ◽  
Anna Kharlamova ◽  
Andrey Makarov ◽  
Galina Kurlyandskaya ◽  
Andrey Svalov
Keyword(s):  
Thin Film ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Easy Magnetization Axis ◽  
Magnetic Characteristics ◽  
Easy Magnetization ◽  
Saturation Field ◽  
Glass Substrates ◽  
Magnetization Axis ◽  
Ferromagnetic Layers

The results on investigation of structural and magnetic characteristics of Co/Cu/Co thin-film systems obtained by magnetron sputtering on glass substrates are presented. The thickness of Co layers in all samples is equal to 5 nm and the Cu layer is varied from 0.5 to 4 nm. It is found that the saturation field, HS, oscillates in magnitude with increasing Cu layer thickness with the period of the order of 1 nm. The maximum values of HS are observed for tCu = 1.4, 2.2 and 3.2 nm. The hysteresis loops measured for these samples in a magnetic field applied along the easy magnetization axis have a two-step form, and for other tCu – rectangular one. The obtained results are explained by the presence of exchange coupling between the ferromagnetic layers through a Co spacer and its oscillating behavior with changing tCu.

scholarly journals Tемпературная зависимость магнитных свойств и магнитополевого поведения тонкопленочных трехслойных Co/Gd/Co систем

2021 ◽  
Vol 63 (10) ◽  
pp. 1542
Author(s):  
А.М. Харламова ◽  
А.В. Макаров ◽  
А.В. Свалов ◽  
Е.Е. Шалыгина
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Coercive Force ◽  
Magnetic Moment ◽  
Hysteresis Loops ◽  
Magnetic Characteristics ◽  
Temperature Changes ◽  
Ion Plasma ◽  
Temperature Dependences ◽  
Oriented Parallel

The results of studies of the temperature dependences of the magnetic properties and magnetic field behavior of thin-film three-layer Co/Gd/Co system, obtained by ion-plasma magnetron sputtering, are present. The thickness of the cobalt layers is 5.0 nm, and the thickness of the Gd layers, tGd, varies from 3.0 to 10.0 nm. The bulk magnetic characteristics of the samples are measured on a vibrating magnetometer at the external magnetic field oriented parallel to the plane of the samples. The influence of the temperature and Gd thickness on the shape of the hysteresis loops, the values of the magnetic moment m and coercive force are discovered. In particular, with the temperature changes from 100 to 300 K, the decrease of the coercive force is observed. At a temperature above 150 K, magnetic moment increases. With increasing thickness of gadolinium, the value of m decreases.

Dependence of Hysteresis Loops on Thickness of Thin Nickel Films Prepared by RF Sputtering

2011 ◽  
Vol 335-336 ◽  
pp. 1443-1447 ◽  
Author(s):  
Watcharee Rattanasakulthong ◽  
Pichai Sirisangsawang ◽  
Supree Pinitsoontorn ◽  
Chitnarong Sirisathitkul
Keyword(s):  
Rf Sputtering ◽  
Hysteresis Loops ◽  
Perpendicular Anisotropy ◽  
X Ray Diffraction ◽  
Saturation Field ◽  
X Ray ◽  
Nickel Films ◽  
Glass Substrates ◽  
Plane Anisotropy ◽  
Thin Nickel

Nickel films of varying thicknesses between 70 and 300 nm were deposited on glass substrates by RF sputtering and their broad (111) FCC peaks were identified by X-ray diffraction. The surface roughness and sub-micron grains were revealed by scanning electron microscopy. According to vibrating sample magnetometry, the films showed hysteresis loops with comparable coercive field and saturation field for the in-plane and perpendicular magnetizations. The increase in thickness substantially increased the magnetization and the squareness of the Ni films. The thickness can be classified into 2 regimes by the variation of squareness. The films are thinner than 200 nm showed the in-plane anisotropy whereas the perpendicular anisotropy was developed in the case of the thickness above 200 nm.

Structural and Magnetic Properties of e-Beam Prepared CoxPt1-x Alloy Films

1993 ◽  
Vol 313 ◽  
Author(s):  
J.V. Harzer ◽  
B. Hillebrands ◽  
I.S. Pogosova ◽  
M. Herrmann ◽  
G. Güntherodt ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
Domain Model ◽  
Exchange Constant ◽  
Saturation Field ◽  
Alloy Films ◽  
X Ray ◽  
Scattering Measurements ◽  
Structural And Magnetic Properties

ABSTRACTWe have investigated structural and magnetic properties of CoPt alloy films with strong perpendicular magnetic anisotropy in the thickness range between 100Å and 400A. From a detailed x-ray analysis we find highly (111) -textured CoPt Microcrystal-lites in all samples. STM studies reveal a granular topography with grain diameters of up to 250Å. Measurements of hysteresis loops yield a saturation field which increases with thickness, and which is consistent with a freely mobile domain Model. Brillouin light scattering measurements of the frequencies of the surface and standing spin wave modes yield a bulk exchange constant, which is strongly dependent on the Pt content.

scholarly journals ION-PLASMA DEPOSITION OF THIN QUASICRYSTALLINE Al-Cu-Fe AND Al-Cu-Co FILMS

2020 ◽  
pp. 145-150
Author(s):  
S.I. Ryabtsev ◽  
O.V. Sukhova
Keyword(s):  
Electrical Resistivity ◽  
Plasma Deposition ◽  
Coherent Scattering ◽  
Room Temperature Resistivity ◽  
Ceramic Substrates ◽  
X Ray ◽  
Plasma Sputtering ◽  
Ion Plasma ◽  
Transmission Electron ◽  
Cu Film

Al-Cu-Fe and Al-Co-Cu thin films were firstly deposited on sodium chloride or glass-ceramic substrates by modernized method of three-electrode ion-plasma sputtering. The nominal compositions of the films were chosen in the regions of quasicrystalline phases formation. The as-sputtered films were typically 85 to 260 nm thick. The films were annealed at temperatures ranging from 873 to 923 K for 10 min…3 h. The structure of films was studied by scanning and transmission electron microscopy and X-ray analysis. Electrical properties were determined by a fourprobe method. The as-deposited Al-Cu-Fe film was found to consist of isolated quasicrystalline nanoparticles of icosahedral i-phase. With substitution of Fe for Co in Al-Co-Cu film, X-ray amorphous phase and only traces of quasicrystalline decagonal D-phase were revealed. After annealing, the films were predominately quasicrystalline due to transformation of metallic phases into quasicrystalline. At the same time, the size of coherent scattering regions for quasicrystals increased by two times from ~ 3 to 6 nm. Measurements of electrical resistivity showed that no phase transformations occurred in Al-Cu-Fe film up to 723 K and in Al-Co-Cu film up to 640 К. With following increase in temperature, electrical resistivity of Al-Cu-Fe film increased by six orders of magnitude (up to 6∙107 Ω/sq). In contrast, electrical resistivity of Al-Co-Cu film decreased by ~ 2 times. After cooling to room temperature, resistivity of Al-Cu-Fe film equaled to ~ 3∙105 Ω/sq and that of Al-Co-Cu film – to 8.7 Ω/sq. We concluded that Al-Cu-Fe thin film is more suitable candidate for application as precise high-ohmic materials.

The Effect of Dopants on Magnetic Properties of the Ordered Fe65-xAl35-yMx,y (Mx,y=Ga,B,V; X,Y=5,10) Alloys

2012 ◽  
Vol 190 ◽  
pp. 534-537
Author(s):  
E. Voronina ◽  
Eugene P. Yelsukov ◽  
A.V. Korolyov ◽  
H.H. Klauss ◽  
T. Dellmann ◽  
...  
Keyword(s):  
Magnetic State ◽  
Ac Susceptibility ◽  
Hysteresis Loops ◽  
Ternary Alloys ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Alloy ◽  
Magnetic Filed ◽  
Magnetic States

The results of X-ray diffraction, complex in-field (up to 9 T) and temperature (5300 К) Mössbauer and magnetometric studies of the ordered Fe65Al35-хMх (M=Ga, B; x=0,5,10) and Fe65-хVxAl35 (x=5,10) alloys are presented. Analysis of the magnetometry studies shows that the systems Fe65Al35 и Fe65Al35-хGaх (x=5, 10) are characterized by two different magnetic states with essentially distinguishing hysteresis loops and AC susceptibility values. The temperature and external magnetic field values inducing the transition from one magnetic state to another are higher in the Ga-doped alloys than in the reference Fe65Al35 alloy. The boron addition transforms the magnetic state of the initial alloy Fe65Al35 into a ferromagnetic one exhibiting high magnetic characteristics. Substitution of V for Fe in the ternary alloys Fe65-хVxAl35 results in reduction of magnetic characteristics and collapsing of 57Fe hyperfine magnetic filed.

scholarly journals Влияние неравновесных условий синтеза на структуру и оптические свойства аморфных углеродных пленок

2019 ◽  
Vol 127 (8) ◽  
pp. 251
Author(s):  
А.П. Рягузов ◽  
Р.Р. Немкаева ◽  
О.И. Юхновец ◽  
Н.Р. Гусейнов ◽  
С.Л. Михайлова ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Local Structure ◽  
Carbon Films ◽  
Phonon Density ◽  
Plasma Current ◽  
Phonon Density Of States ◽  
Graphite Target ◽  
X Ray ◽  
Plasma Sputtering ◽  
Ion Plasma

Amorphous carbon (a-C) thin films were synthesized by non-equilibrium method of ion-plasma sputtering of graphite target in Ar atmosphere at constant value of plasma current. Studies of the local structure of the carbon films were carried out using Raman spectroscopy method. Using normal distribution for Raman spectra decomposition it was revealed that at synthesis temperatures below 150 C a peak at about 1260 cm-1 occurred, which is characteristic for phonon density of states with sp3-hybridized bonds. In addition, it was shown the dependence of the optical bandgap on the sizes of sp2-site nanostructures and correlation of it with the results of X-ray photoelectron spectroscopy (XPS) in the a-C films.

Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

1983 ◽  
Vol 41 ◽  
pp. 446-447
Author(s):  
William F. Tivol ◽  
Murray Vernon King ◽  
D. F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Heavy Atom ◽  
Isomorphous Substitution ◽  
X Ray Diffraction ◽  
Salt Solutions ◽  
X Ray ◽  
Isomorphous Replacement ◽  
Structure Factors ◽  
Diffraction Structure ◽  
The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

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