scholarly journals Structural and Magnetic Properties of Ni0.8Fe0.2/Ti Nanoscale Multilayers

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 780 ◽  
Author(s):  
Ricardo López Antón ◽  
Juan A. González ◽  
Juan P. Andrés ◽  
Andrei V. Svalov ◽  
Galina V. Kurlyandskaya
Keyword(s):  
Magnetic Properties ◽  
Temperature Dependence ◽  
Layered Structure ◽  
Magnetic Measurements ◽  
Hysteresis Loops ◽  
Multilayered Structures ◽  
X Ray ◽  
Structural And Magnetic Properties

The influence of the thickness of the Ni0.8Fe0.2 (Permalloy, Py) layers on the structural and magnetic properties of magnetron sputtered Py/Ti multilayers was studied. The thickness of the Py layers was varied in the interval of 8 to 30 Å. X-ray reflectivity scans evidence the existence of a well-defined layered structure in all the samples considered, but also the presence of a complex intermixed interface. The shape of both the temperature dependence of magnetization and the hysteresis loops of the multilayered structures depends strongly on Py thickness. Magnetic and reflectivity measurements were comparatively analyzed in order to better understand the structure of the samples, and specifically, their interfaces. In particular, the presence of small superparamagnetic Py at the interfaces of the samples, especially evident in the samples with the thinnest Py layers, seems confirmed by the magnetic measurements, agreeing well with the reflectivity results.

Structural and magnetic properties of DyCo4−xFexGa compounds

2010 ◽  
Vol 25 (S1) ◽  
pp. S31-S35
Author(s):  
W. H. Zhang ◽  
J. Q. Li ◽  
Y. J. Yu ◽  
F. S. Liu ◽  
W. Q. Ao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Uniaxial Anisotropy ◽  
Solubility Limit ◽  
Spin Reorientation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Spin Reorientation Transition ◽  
Structural And Magnetic Properties

The structural and magnetic properties of the DyCo4−xFexGa compounds with x=0, 0.5, 1, and 1.5 have been investigated by X-ray diffraction and magnetic measurements. Powder X-ray diffraction analysis reveals that each of the DyCo4−xFexGa compounds has a hexagonal CaCu5-type structure (space group P6/mmm). The Fe solubility limit in DyCo4−xFexGa is x<1.5. The higher the value of x, the larger the unit-cell parameters a, c, V, and the 3d-sublattice moment but the smaller the 3d uniaxial anisotropy. Magnetic measurements show that the Curie temperature of DyCo4−xFexGa increases from 498 K for x=0 to 530 K for x=1.5, the compensation temperature Tcomp decreases from 286 K for x=0 to 238 K for x=1.5, and the spin-reorientation transition temperature increases from 403 K for x=0 to 530 K for x=0.5. No spin-reorientation transition was found in the samples with x=1.0 and 1.5. The saturation magnetization of DyCo4−xFexGa measured at 173 K increases but the magnetization measured at 300 K decreases with increasing Fe content x.

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.

Structural and Magnetic Properties of La0.7Sr0.3Mn1-xNixO3 (x=0.05, 0.1, 0.2, 0.3, 0.4)

2011 ◽  
Vol 1327 ◽  
Author(s):  
Thomas F. Creel ◽  
Jinbo B. Yang ◽  
Mehmet Kahveci ◽  
Jagat Lamsal ◽  
Satish K. Malik ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Neutron Diffraction ◽  
Diffraction Data ◽  
Magnetic Measurements ◽  
Magnetic Ordering ◽  
Neutron Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Structural And Magnetic Properties

ABSTRACTWe have studied the structural and magnetic properties of La0.7Sr0.3Mn1-xNixO3 (x=0.05, 0.10, 0.20, 0.30, and 0.40) perovskites using x-ray and neutron diffraction and magnetic measurements. To our knowledge, there exists no neutron diffraction data available for this group of perovskite compositions. Neutron (λ = 1.479Å) and x-ray (λ = 1.5481Å; Cu Kα) powder diffraction indicate that for x ≥ 0.1 all samples are two-phase with a rhombohedral perovskite structure (space group R-3c) and a small amount of NiO (space group Fm3m). Neutron diffraction data for the perovskite phase at 12K and 300K show ferromagnetic ordering for x ≤ 0.2 and antiferromagnetic ordering for x = 0.4. However, for x = 0.3, neutron diffraction data at 12K show coexisting ferromagnetic and antiferromagnetic ordering while at 300K no magnetic ordering is found. Magnetic measurements indicate that the Curie temperature decreases with increasing Ni content. The NiO phase for all samples was found to have antiferromagnetic ordering at 12K and 300K. The magnetic measurements are consistent with the neutron diffraction data and together indicate long-range magnetic ordering for samples at low temperature and transitions from ferromagnetic to paramagnetic to antiferromagnetic ordering for samples at room temperature.

Structural and magnetic properties of pure and cobalt doped Gallium Nitride nanocrystals

2010 ◽  
Vol 1257 ◽  
Author(s):  
Vottikondala Ganesh ◽  
Suresh Sundaram ◽  
Krishnan Baskar
Keyword(s):  
Magnetic Properties ◽  
Gallium Nitride ◽  
Magnetic Measurements ◽  
Raw Materials ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Co Doped

AbstractIn the present study pure and doped gallium nitride (GaN) nanocrystals were synthesized using gallium trichloride (GaCl3), ethylene diamine tetra acetic acid (EDTA) and cobalt chloride as raw materials at a temperature of 900 °C in ammonia (NH3) atmosphere. The XRD spectrum for pure and cobalt doped GaN nanocrystals shows the formation of single phase wurtzite structure. No impurity phases were observed in the X-ray diffraction pattern for 5% Co doped sample whereas secondary phases were observed when the doping concentration exceeds 5 %. Shift in X-ray diffraction peaks were observed in Co doped samples towards lower angle side compared to pure GaN, it confirms that the Co atoms introduces in to the GaN lattice. Transmission electron microscopy images were taken for pure and Co doped GaN. Hexagonal morphology was observed in pure GaN samples. The average size of the particle was found to be ˜20 nm for pure and Co doped GaN. The magnetic measurements were carried out for the Co (5% & 10%) doped samples both at 10K and 300K. Clear hysteresis loop in the magnetization curve suggest the presence of ferromagnetic behavior in cobalt doped GaN. Temperature dependent magnetization (M-T) measurements were also carried out for doped samples using Super Conducting Quantum Interface Device (SQUID) from 10K to 300K The results have been discussed and correlated to structural and magnetic properties of the materials.

Structural and Magnetic Properties of Untwinned Yba2Cu3O6+x Single Crystals

1989 ◽  
Vol 169 ◽  
Author(s):  
Debra L. Kaiser ◽  
Frank W. Gayle ◽  
Lydon J. Swartzendruber ◽  
Winnie Wong-Ng ◽  
Steven F. Watkins ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Crystals ◽  
Flux Pinning ◽  
Magnetic Measurements ◽  
Mirror Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Low Levels ◽  
Superconducting Onset Temperature

AbstractWe have conducted structural and magnetic investigations on thermomechanically-detwinned YBa2Cu3O6+x single crystals. Single crystal x-ray diffraction studies on a fully untwinned crystal with a superconducting onset temperature of 54 K have revealed that oxygen atoms in the basal plane are offset from the crystallographic mirror plane in the a direction, leading to “zig-zag” Cu-O chains. Magnetic measurements on untwinned and twinned crystals at 77 K indicate low levels of flux pinning in both crystals, with a slightly larger amount of pinning in the twinned crystal.

Giant Magnetoresistance in Co/Ag Multilayers

1993 ◽  
Vol 313 ◽  
Author(s):  
M. Tan ◽  
J. A. Barnard ◽  
M. R. Parker ◽  
D. Seale
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Layered Structure ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Antiferromagnetic Coupling ◽  
High Angle ◽  
X Ray ◽  
Field Sensitivity

ABSTRACTThe Magnetoresistance (MR), Magnetic properties, and crystal structure of dc magnetron sputtered CO/Ag periodic multilayers have been investigated. The Co layer thickness was fixed at -30 Å while the thickness of the Ag layer was systematically varied. ‘Giant’ magnetoresistance was observed. The MR ratio has been found to decline monotonically with increasing Ag thickness in the range 30 Å to 107 Å. Although the maximum room temperature MR ratio is a Modest 4.78%, a more technologically significant measurement of field sensitivity (MR ratio/FWHM of the MR vs. H peak) is a promising 0.1%/Oe at its best. The effect of the number of bilayer units has also been examined and no substantial differences were noted between multilayers containing 8, 9, and 10 bilayer units. Coercivities as determined by both magnetometer and the splitting of the MR peaks are in agreement and increase from 25 to 38 Oe with increasing Ag thickness. Evidence for antiferromagnetic coupling is apparent in the hysteresis loops. High angle X-ray diffractometry (HXRD) in the θ-2θ mode revealed a strong Ag (111) texture in the film, with satellite peaks indicating a layered structure. Low angle XRD (LXRD) also yielded broad superlattice peaks in all samples at least to the second order.

Structural and Magnetic Properties of Well-Ordered Inverted Core-Shell α-Cr2O3/ α-MxCr2-xO3 (M=Co, Ni, Mn, Fe) Nanoparticles

MRS Advances ◽  
2016 ◽  
Vol 1 (34) ◽  
pp. 2387-2392 ◽  
Author(s):  
M.D. Hossain ◽  
S. Dey ◽  
R. A. Mayanovic ◽  
M. Benamara
Keyword(s):  
Magnetic Properties ◽  
Oxygen Vacancy ◽  
Magnetic Measurements ◽  
Hysteresis Loops ◽  
Core Shell ◽  
Magnetic Polaron ◽  
Zero Field ◽  
Shell Nanoparticles ◽  
Structural And Magnetic Properties ◽  
Core Shell Nanoparticles

ABSTRACTMagnetic core shell nanoparticles (NPs) have potential for applications in magnetic random access memory, spintronic devices, and drug delivery systems. Our investigations are focused on the synthesis of inverted core shell nanoparticles and characterization of their structural and magnetic properties. By using our hydrothermal nanophase epitaxy technique, we are able to synthesize well-ordered α-Cr2O3@α-MxCr2-xO3 (M = Co, Ni, Mn, Fe) inverted core-shell nanoparticles. This typically results in the formation of novel phases of MxCr2-xO3 shells having ferromagnetic/ferrimagnetic (FM/FiM) spin ordering and an antiferromagnetic (AFM) Cr2O3 core structure. The combined results from XRD and high-resolution TEM (HRTEM) provide evidence of the presence of corundum phase both in the shell and in the core regions. HRTEM results also show a sharp interface exhibiting epitaxial atomic registry of shell atoms over highly ordered core atoms whereas TEM-EDX analyses show that the M atoms reside predominantly in the shell regions. The XPS analyses of the NPs indicate the M transition metals incorporated in the shell are in the +2 oxidation state. Magnetic measurements show well developed hysteresis loops: The field cooled hysteresis loops reveal horizontal shifts in the applied field axis and vertical shifts in the magnetization axis, relative to the zero-field cooled hysteresis loops. This provides direct evidence for the exchange bias effect between the AFM α-Cr2O3 core and the FM/FiM α-MxCr2-xO3 shell. The XPS data are consistent with oxygen vacancy formation in order to maintain charge neutrality upon substitution of the M2+ ion for the Cr3+ ion in the α-MxCr2-xO3 shell. The FM/FiM ordering in the shell may at least partially result from the F-center exchange coupling between the oxygen-vacancy induced bound magnetic polaron and nearby cations.

ANNEALING EFFECT ON THE INDUCED MAGNETISM OF PLATINUM IN FePt NANOPARTICLES

2007 ◽  
Vol 21 (18) ◽  
pp. 1189-1196 ◽  
Author(s):  
F. WILHELM ◽  
A. ROGALEV ◽  
P. POULOPOULOS ◽  
M. ANGELAKERIS ◽  
J. TSIAOUSSIS ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Circular Dichroism ◽  
Annealing Effect ◽  
Fept Nanoparticles ◽  
X Ray ◽  
Remanence Ratio ◽  
Structural And Magnetic Properties ◽  
Coercivity Field ◽  
Average Size ◽  
Magnetic Circular Dichroism Spectra

Effect of annealing on structural and magnetic properties of non-equatomic chemically synthesized FePt nanoparticles with an average size of 3.2 nm diameter is reported. Annealing of the particles at 700°C resulted in the increase of particles size and the enhancement of total magnetization and coercivity, the latter could be attributed to a transformation from disordered to ordered crystallographic phase. Although the system is far from optimum "equatomic" stoichiometry, coercivity field of 1.1 kOe was obtained at 10 K together with remanence ratio of 0.55. X-ray magnetic circular dichroism spectra recorded at the Pt L 2,3 edges on annealed samples revealed the enhancement of magnetic moment induced on Pt atom.

Influence of Alloying Additions on Enhancement of Soft Magnetic Properties Effect and Crystallization in FeXSiB (X=Cu, V, Co, Zr, Nb) Amorphous Alloys

2007 ◽  
Vol 130 ◽  
pp. 171-174 ◽  
Author(s):  
Z. Stokłosa ◽  
G. Badura ◽  
P. Kwapuliński ◽  
Józef Rasek ◽  
G. Haneczok ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Crystallization Process ◽  
Annealing Temperature ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
X Ray ◽  
Second Stage ◽  
Transmission Electron

The crystallization and optimization of magnetic properties effects in FeXSiB (X=Cu, V, Co, Zr, Nb) amorphous alloys were studied by applying X-ray diffraction methods, high resolution transmission electron microscopy (HRTEM), resistometric and magnetic measurements. The temperatures of the first and the second stage of crystallization, the 1h optimization annealing temperature and the Curie temperature were determined for different amorphous alloys. Activation energies of crystallization process were obtained by applying the Kissinger method. The influence of alloy additions on optimization effect and crystallization processes was carefully examined.

Sign in / Sign up

Export Citation Format

Share Document