Hysteresis loops of a periodic multilayered structure with antiferromagnetic coupling

2004 ◽  
Vol 49 (6) ◽  
pp. 1042-1045 ◽  
Author(s):  
D. I. Sementsov ◽  
A. M. Shutyi
Keyword(s):  
Hysteresis Loops ◽  
Multilayered Structure ◽  
Antiferromagnetic Coupling

Giant Magnetoresistance in As-Sputter-Deposited Au/NiFe Multilayer Thin Films

1994 ◽  
Vol 343 ◽  
Author(s):  
W. Y. Lee ◽  
G. Gorman ◽  
R. Savoy
Keyword(s):  
Thin Films ◽  
Exchange Coupling ◽  
Giant Magnetoresistance ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Multilayer Films ◽  
Antiferromagnetic Coupling ◽  
Multilayer Thin Films ◽  
Glass Substrates ◽  
Sputter Deposited

ABSTRACTGiant magnetoresistance with low saturation fields (Hs’s) is reported in Au and permalloy (Ni0.82Fe0.18) or Co-doped permalloy multilayer thin films as-deposited on Ta-overcoated Si and glass substrates. A ΔR/R as high as 4.0% with ≈25 Oe Hs was observed at 295 K for the film consisting of 10 layers of 24 Å Au/13 Å Ni0.82Fe0.18 deposited on a 3 Å Ta-overcoated glass at 50 °C. A Hs value as low as ≈20 Oe with a 15% smaller ΔR/R has been observed for the films with a thicker (e.g., 50 Å) Ta underlayer. Magnetic hysteresis loops of these films indicate the presence of antiferromagnetic exchange coupling between the Ni0.82Fe0.18 layers. This exchange coupling is much smaller for the multilayer films without the Ta underlayer, resulting in a 6x smaller ΔR/R and lOx larger Hs observed for these films. Results of x-ray diffraction analysis indicate stronger (111) texturing for the multilayer films with a Ta underlayer, consistent with the stronger antiferromagnetic coupling between the the Ni0.82Fe0.18 layers in the film. The addition of 2–10 % Co moderately increases the ΔR/R value, but also increases substantially the Hs (up to ≈200 Oe).

Structural, Magnetic, and Magneto-Optical Properties of Nanocrystalline Face Centered Cubic Co70Cr30/Pt Multilayers with Perpendicular Magnetic Anisotropy

2007 ◽  
Vol 7 (12) ◽  
pp. 4278-4284 ◽  
Author(s):  
E. Th. Papaioannou ◽  
M. Angelakeris ◽  
P. Poulopoulos ◽  
I. Tsiaoussis ◽  
C. Rüdt ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
Multilayered Structure ◽  
Ultraviolet Region ◽  
Temperature Hysteresis ◽  
Face Centered Cubic ◽  
Geometry Configuration ◽  
Face Centered ◽  
Magneto Optic

Co70Cr30 alloyed layers are combined with extremely thin Pt layers in order to produce novel face-centered-cubic multilayered films to be considered as a potential perpendicular magnetic recording medium. The films were grown on Si, glass and polyimide substrates by e-beam evaporation at a temperature slightly higher than room temperature. The multilayered structure of the films was verified by X-ray diffraction experiments. Plane-view transmission electron microscopy images have revealed the formation of very small grains in the range of 7–9 nm. Hysteresis loops as a function of temperature were recorded via the magneto-optic Kerr effect in the polar geometry configuration. The system exhibits perpendicular magnetic anisotropy, which enhances with decreasing temperature. Hysteresis loops with a squareness of 1 and a coercivity of 1.45 kOe were obtained at 10 K. Furthermore, complete magneto-optic spectra of the films are recorded, showing a strong magneto-optic enhancement in the ultraviolet region at around 4.5 eV.

Magnetization Processes Analysis in Co-Cu Superlattices

1989 ◽  
Vol 151 ◽  
Author(s):  
J. P. Rebouillat ◽  
G. Fillion ◽  
B. Dieny ◽  
A. Cebollada ◽  
J. M. Gallego ◽  
...  
Keyword(s):  
Hysteresis Loops ◽  
Antiferromagnetic Coupling ◽  
Magnetization Measurements ◽  
The Individual ◽  
Magnetization Processes

ABSTRACTThe analysis of the magnetization measurements performed on two Co-Cu multilayers confirm the antiferromagnetic coupling already observed with neutron experiments. Both exchange and anisotropy energies are taken into account and estimated. Their competitive role in the individual moment orientation leads to typical moment arrangements and hysteresis loops.

Calculation of Magnetization Processes in Multilayers with Antiferromagnetic Coupling between Adjacent Layers

1989 ◽  
Vol 151 ◽  
Author(s):  
B. Dieny ◽  
J. P. Gavigan ◽  
J. P. Rebouillat
Keyword(s):  
Uniaxial Anisotropy ◽  
Hysteresis Loops ◽  
Antiferromagnetic Coupling ◽  
Propagation Mechanism ◽  
Multilayer Systems ◽  
Number Of Layers ◽  
Magnetization Processes

ABSTRACTThis paper presents calculations of hysteresis loops in ferromagnetic multilayer systems of cubic or uniaxial anisotropy with antiferromagnetic coupling between adjacent layers. The case of a bilayer has been systematically studied as a function of the strenght of the anisotropy. The two limiting cases corresponding to either a coherent rotation of the magnetization or to a non-dissipative nucleation-propagation mechanism are investigated. The influence of the number of layers is also discussed.

MAGNETIC AND ELECTRICAL PROPERTIES OF ELECTRON BEAM GUN DEPOSITED [Mn/Al] MULTILAYERED FILMS

2015 ◽  
Vol 8 (3) ◽  
pp. 2231-2239
Author(s):  
Sankarappa Talari ◽  
R. Ramanna ◽  
T. Sujatha ◽  
J.S. Ashwajeet ◽  
P.J. Sadashivaiah
Keyword(s):  
Electron Beam ◽  
High Vacuum ◽  
Hysteresis Loops ◽  
Grazing Incidence ◽  
Magnetic Multilayers ◽  
Antiferromagnetic Coupling ◽  
Grain Sizes ◽  
Atomic Force ◽  
Evaporation Technique ◽  
Hopping Models

By following electron beam gun evaporation technique, the magnetic multilayers in the configuration, [Mn(60nm)/Al(20nm)]n; n =1, 2 and 9 were deposited at 473K,  under high vacuum conditions. From grazing incidence X- ray diffraction (GIXRD) studies, the grain sizes were determined and they were in the order of few nanometers. Atomic force microscope (AFM) were employed to study surface structure and grain sizes. The magnetization as a function of field at 150K and 200K have been measured using the MPMS SQUID - vibrating sample magnetometer (VSM). From the hysteresis loops, coercive field, saturation magnetization, remanent magnetization and antiferromagnetic coupling were determined. All the three films hinted at the existence of at antiferromagnetic interaction between Mn layers through Al layer. Electrical resistivity in the temperature range from 5K to 300K has been measured. Films exhibited semiconducting to metallic transition. The power law variation of resistivity with temperature was established for the metallic region. Conductivity data for semiconducting region of a film has been analysed using polaran hopping models, activation energy and density of states at Fermi level were established. This is for the first time that antiferromagnetic coupling between Mn layers through interfacer layer and semiconducting to metallic transition have been noticed in the present configuration of [Mn/Al] multilayers.

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.

Exchange bias and anomalous vertical shift of the hysteresis loops in milled Fe/MnO2 material

2006 ◽  
Vol 299 (1) ◽  
pp. 11-20 ◽  
Author(s):  
E.C. Passamani ◽  
C. Larica ◽  
C. Marques ◽  
J.R. Proveti ◽  
A.Y. Takeuchi ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Hysteresis Loops ◽  
Vertical Shift

Interfacial antiferromagnetic coupling and high spin polarization in metallic phthalocyanines

2021 ◽  
Vol 103 (2) ◽  
Author(s):  
Junwei Tong ◽  
Feifei Luo ◽  
Liuxia Ruan ◽  
Guohuai Liu ◽  
Lianqun Zhou ◽  
...  
Keyword(s):  
Spin Polarization ◽  
High Spin ◽  
Antiferromagnetic Coupling ◽  
High Spin Polarization
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