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.

Domain Configurations, Bloch Walls, and Magnetization Processes in Iron Whiskers from D.C. to 200 kHz. Theory and Experiment. I

1972 ◽  
Vol 50 (7) ◽  
pp. 710-720 ◽  
Author(s):  
B. Heinrich ◽  
A. S. Arrott
Keyword(s):  
Eddy Currents ◽  
Elastic Membrane ◽  
Magnetization Measurements ◽  
Wide Range ◽  
Elastic Wall ◽  
Iron Whiskers ◽  
Magnetization Processes ◽  
Theory And Experiment

Bloch walls in iron whiskers have been studied by direct magnetization measurements. Of several types of domain configurations the simplest, the Landau structure, is readily identified from the a.c. permeability. The behavior of this structure over a wide range of frequencies is accounted for by a model which treats the wall as an elastic membrane attached to two springs on its ends. The stiffness is shown to be magnetostatic in origin. The elastic wall is shown to be damped in its motion by eddy currents. The qualitative aspects of the behavior are well accounted for and some numerical consistencies are found.

Comparison of static hysteresis models subject to arbitrary magnetization waveforms

2017 ◽  
Vol 36 (3) ◽  
pp. 774-790 ◽  
Author(s):  
Martin Petrun ◽  
Simon Steentjes ◽  
Kay Hameyer ◽  
Drago Dolinar
Keyword(s):  
Design Methodology ◽  
Hysteresis Loops ◽  
Magnetization Curves ◽  
Hysteresis Model ◽  
Content Type ◽  
The Individual ◽  
Practical Implications ◽  
Excitation Waveform ◽  
Arbitrary Magnetization ◽  
Selection Of

Purpose This paper aims to compare different static history-independent hysteresis models (mathematical-, behavioural- and physical-based ones) and a history-dependent hysteresis model in terms of parameter identification effort and accuracy. Design/methodology/approach The discussed models were tested for distorted-excitation waveforms to explore their predictions of complex magnetization curves. Static hysteresis models were evaluated by comparing the calculated and measured major and minor static hysteresis loops. Findings The analysis shows that the resulting accuracy of the different hysteresis models is strongly dependent on the excitation waveform, i.e. smooth excitations, distorted flux waveforms, transients or steady-state regimes. Obtained results show significant differences between predictions of discussed static hysteresis models. Research limitations/implications The general aim was to identify the models on a very basic and limited set of measured data, i.e. if possible using only the measured major static loop of the material. The quasi-static major hysteresis loop was measured at Bmax = 1.5 T. Practical/implications The presented analysis allows selection of the most-suited hysteresis model for the sought-for application and appraisal of the individual limitations. Originality/value The presented analysis shows differences in intrinsic mechanisms to predict magnetization curves of the majority of the well-known static hysteresis models. The results are essential when selecting the most-suited hysteresis model for a specific application.

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).

A study on pinned layer magnetization processes in different antiferromagnetic coupling systems of spin-valves

2000 ◽  
Vol 87 (9) ◽  
pp. 5729-5731 ◽  
Author(s):  
Zhijun Yang ◽  
Dehua Han ◽  
Sining Mao ◽  
Hong Wang ◽  
Ghanim Al-Jumaily ◽  
...  
Keyword(s):  
Spin Valves ◽  
Antiferromagnetic Coupling ◽  
Magnetization Processes ◽  
Layer Magnetization

Growth and Magnetism of Natural Multilayers

2011 ◽  
Vol 15 ◽  
pp. 95-103 ◽  
Author(s):  
Panagiotis Poulopoulos ◽  
S.D. Pappas ◽  
Vassilios Kapaklis ◽  
P.E. Jönsson ◽  
E.T. Papaioannou ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Room Temperature ◽  
Vacuum Chamber ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
Optical Recording ◽  
High Quality ◽  
Simple Method ◽  
Multilayered System ◽  
The Individual

. In this work, we present a simple method to fabricate high quality Ni/NiO multilayers with the use of a single magnetron sputtering head. Namely, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer (~ 1nm) is formed by natural oxidation. The process is reproducible and the result is the formation of a multilayer with excellent layering. Magnetization hysteresis loops recorded at 5 K and room temperature reveal a tendency for perpendicular magnetic anisotropy as the thickness of the individual Ni layers decreases. It is shown that the Ni/NiO interface has sizeable positive surface/interface anisotropy, i.e. it favors the development of perpendicular magnetic anisotropy. This is rather unusual for a Ni-based multilayered system and may render Ni/NiO multilayers useful for magneto-optical recording applications.

IRREVERSIBLE SUSCEPTIBILITY OF INITIAL MAGNETIZATION CURVES DEFINED BY ENERGY CONSIDERATION

2007 ◽  
Vol 21 (21) ◽  
pp. 3707-3717 ◽  
Author(s):  
G. GOEV ◽  
V. MASHEVA ◽  
M. MIKHOV ◽  
J. GESHEV
Keyword(s):  
Magnetic Field ◽  
Hysteresis Loops ◽  
Model System ◽  
Magnetization Curves ◽  
Maximum Magnetic Field ◽  
Initial Magnetization ◽  
Curve Method ◽  
Energy Consideration ◽  
Minor Hysteresis Loops ◽  
Magnetization Processes

A method for the estimation of reversible and irreversible susceptibilities of initial magnetization curves has been developed. It deals with the energy necessary for magnetizing and demagnetizing the sample, but neither with the nature of the magnetization processes nor with a specific type of anisotropy, so it could be applied for a wide variety of real materials. A set of minor hysteresis loops of an initially demagnetized sample, plotted with progressively increasing maximum magnetic field, has been used. The obtained results showed excellent agreement with those calculated by the remanence curve method for a Stoner–Wohlfarth model system.

scholarly journals From a square core to square opening: structural diversity and magnetic properties of the oxo-bridged [CrIIINbV] complexes

2018 ◽  
Vol 47 (12) ◽  
pp. 4183-4190 ◽  
Author(s):  
Marijana Jurić ◽  
Lidija Androš Dubraja ◽  
Jasminka Popović ◽  
Krešimir Molčanov ◽  
Filip Torić ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Dft Calculations ◽  
Structural Diversity ◽  
Antiferromagnetic Coupling ◽  
Magnetization Measurements

Three oxo-bridged [CrIIINbV] compounds exhibit antiferromagnetic coupling between CrIII ions mediated through the diamagnetic –O–NbV–O– bridge, as observed by magnetization measurements and DFT calculations.

A Variational Model of Ferroelectric Microstructure

2008 ◽  
Author(s):  
J. E. Huber ◽  
A. C. F. Cocks
Keyword(s):  
Single Crystal ◽  
Degrees Of Freedom ◽  
Domain Walls ◽  
Hysteresis Loops ◽  
Variational Model ◽  
Ferroelectric Crystal ◽  
Individual Domain ◽  
Thermodynamic Variables ◽  
The Individual ◽  
Uniaxial Compressive Stress

A simple model of the evolution of ferroelectric microstructure in single crystals is developed by using variational methods to minimize a functional based on free energy and dissipation. The thermodynamic variables in this formulation correspond to the positions of a set of domain walls within a single ferroelectric crystal. The total dissipation rate is taken to be a function of the velocities of the individual domain walls. With only two-degrees of freedom, a model of this type has sufficient richness to reproduce many of the observed features found in the single crystal response of a tetragonal ferroelectric. This includes the dielectric hysteresis, butterfly hysteresis, and the variation of the hysteresis loops under uniaxial compressive stress. Additional degrees of freedom can be used to capture multi-axiality. The model also highlights the marked differences in response that should occur when a single crystal is subjected to different boundary conditions.

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