DETERMINATION OF THE EQUIVALENT ANISOTROPY PROPERTIES OF POLYCRYSTALLINE MAGNETIC MATERIALS: THEORETICAL ASPECTS AND NUMERICAL ANALYSIS

The aim of this paper is the determination of the equivalent anisotropy properties of polycrystalline magnetic materials, modeled as an assembly of monocrystalline grains with a stochastic spatial distribution of easy axes. The theory of Γ-convergence is here adopted to homogenize the anisotropic contribution in the energy functional and derive the equivalent anisotropy properties. The reliability of this approach is investigated focusing on the computation of the static hysteresis loops of polycrystalline magnetic thin films, starting from the numerical integration of the Landau–Lifshitz–Gilbert equation.

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Determination of magnetic parameters in magnetic thin films by torque measurement

IEEE Transactions on Magnetics ◽

10.1109/20.11670 ◽

1988 ◽

Vol 24 (2) ◽

pp. 1995-1997 ◽

Cited By ~ 2

Author(s):

M. Tejedor ◽

A. Fernandez ◽

B. Hernando

Keyword(s):

Thin Films ◽

Magnetic Thin Films ◽

Torque Measurement ◽

Magnetic Parameters

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Computer calculation of fanning spin structure in magnetic thin films and determination of exchange stiffness constant

Czechoslovak Journal of Physics ◽

10.1007/bf01691549 ◽

1971 ◽

Vol 21 (4-5) ◽

pp. 537-540

Author(s):

S. Chikazumi ◽

N. Imamura

Keyword(s):

Thin Films ◽

Spin Structure ◽

Computer Calculation ◽

Magnetic Thin Films ◽

Stiffness Constant

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Micromagnetic Simulations Of Domain Structures In Thin Films And Bulk Hard Magnets

Microscopy and Microanalysis ◽

10.1017/s1431927600013507 ◽

1999 ◽

Vol 5 (S2) ◽

pp. 36-37

Author(s):

Zhi-Xiong Cai ◽

Yimei Zhu

Keyword(s):

Thin Films ◽

Magnetic Materials ◽

Domain Structure ◽

Easy Axis ◽

Magnetic Thin Films ◽

Magnetic Films ◽

Electron Holography ◽

Bulk Materials ◽

Hard Magnetic Materials ◽

Domain Structures

The shape anisotropy of a magnetic thin film competes with the easy-axis anisotropy, which gives rise to different domain structures compared to the bulk magnetic materials. Recent Lorentz microscope and electron holography and differential-phase-contrast experiments show complex domain structures with features not found in bulk materials seen by magneto-optic method.In this report we use micromagnetic simulation techniques to study the effect of thickness on the domain structure of magnetic thin films with various orientations relative to the easy axis and compare with those in the bulk materials. The results of the simulations can be used to compare with the data obtained using electron holography experiments to give us quantitative understanding of the domain structure in hard magnetic materials.We model the magnetic films with an array of dipoles of size 16×l6×Lz, where Lz the thickness of the sample.

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Numerical analysis on thickness effect of magnetic thin films on conduction noise absorption in microstrip line

Metals and Materials International ◽

10.1007/s12540-011-1018-y ◽

2011 ◽

Vol 17 (5) ◽

pp. 805-810

Author(s):

Gi-Bong Ryu ◽

Sung-Soo Kim

Keyword(s):

Thin Films ◽

Numerical Analysis ◽

Microstrip Line ◽

Magnetic Thin Films ◽

Thickness Effect ◽

Noise Absorption

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Observation of reversed hysteresis loops and negative coercivity in CoFeAlO magnetic thin films

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2005.01.003 ◽

2005 ◽

Vol 295 (2) ◽

pp. 126-131 ◽

Cited By ~ 16

Author(s):

N.D. Ha ◽

T.S. Yoon ◽

E. Gan'shina ◽

M.H. Phan ◽

C.G. Kim ◽

...

Keyword(s):

Thin Films ◽

Hysteresis Loops ◽

Magnetic Thin Films

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Observation of Magnetic Domain Structure of Micro Magnetic Materials and Magnetic Thin Films by Photoemission Electron Microscope (PEEM)

Hyomen Kagaku ◽

10.1380/jsssj.26.19 ◽

2005 ◽

Vol 26 (1) ◽

pp. 19-27 ◽

Cited By ~ 2

Author(s):

Taichi OKUDA ◽

Toyohiko KINOSHITA

Keyword(s):

Thin Films ◽

Electron Microscope ◽

Magnetic Materials ◽

Domain Structure ◽

Magnetic Domain ◽

Magnetic Thin Films ◽

Magnetic Domain Structure ◽

Photoemission Electron

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Experimental determination of interfacial-layer thickness from polarization-voltage hysteresis loops in Pb(Zr0.4Ti0.6)O3 thin films

Applied Physics Letters ◽

10.1063/1.1927270 ◽

2005 ◽

Vol 86 (20) ◽

pp. 202904 ◽

Cited By ~ 16

Author(s):

A. Q. Jiang ◽

C. Wang ◽

B. L. Cheng ◽

Z. H. Chen

Keyword(s):

Thin Films ◽

Experimental Determination ◽

Layer Thickness ◽

Interfacial Layer ◽

Hysteresis Loops ◽

Polarization Voltage ◽

Voltage Hysteresis

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Determination of the Upper Limit for the Cluster Moment Contributing the Giant Magneto Resistance in Laser Deposited Granular Cu-rich Thin Films

MRS Proceedings ◽

10.1557/proc-459-483 ◽

1996 ◽

Vol 459 ◽

Author(s):

V. Madurga ◽

R. J. Ortega ◽

J. Vergara ◽

K. V. Rao

Keyword(s):

Thin Films ◽

Laser Ablation ◽

Cluster Size ◽

Magnetic Hysteresis ◽

Hysteresis Loops ◽

Annealing Temperatures ◽

Upper Limit ◽

Magnetic Hysteresis Loops ◽

Magneto Resistance

ABSTRACTWe have fabricated granular Cu95Co5 thin films by laser ablation-deposition. Within a regime of annealing temperatures, these samples exhibit Giant Magneto Resistance (GMR), typically 5% in 0.5 Tesla at 5 K. The magnetic hysteresis loops are found to show finite coercive fields in the whole temperature range 2 K - 300 K. Below 9 K, the field dependence of the MR shows a split maximum. We interpret the data in terms of coercivity arising from blocking phenomenon of single domain superparamagnetic Co clusters. A quantitative determination of the upper limit for the cluster moment contributing to GMR is estimated to be 17000 μB (a cluster size of 5 nm).

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