A new method of calculating the medium field and the demagnetizing field for MR heads

Suzuki, Yoshio; Ishikawa, Chiaki

doi:10.1109/20.706600

Cited by 19 publications

(3 citation statements)

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“…Output signals were calculated by using a recorded magnetization pattern and a sensitivity function. 27,28) The recorded magnetization pattern was calculated by using the LLG equation; namely, magnetic dots were assumed to be saturated and relaxed. A model of an MR head for calculating the sensitivity function (magnetic field) is shown in Fig.…”

Section: Methods For Calculating Snrmentioning

confidence: 99%

Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.² on a Bit-Patterned Medium

Akagi

Ushiyama

Miyamoto

et al. 2012

Jpn. J. Appl. Phys.

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The second moments of the quark structure functions of the longitudinally M L ρ and transversally M T ρ polarized ρ-mesons are calculated in the framework of QCD sum rules in external fields. The operators of dimension 4 and 6 are taken into account. The results are (µ 2 = 1 GeV 2 ): M L ρ = 0.84 ± 0.08, M T ρ = 0.5 ± 0.1. The large difference between the values of M L ρ and M T ρ indicates that the ρ-meson polarization strongly influences the internal structure. In particular, in the case of the longitudinally polarized ρ-meson the gluon sea is found to be strongly suppressed, it is less than 20 ÷ 25%, whereas in usual hadron case -about 40 ÷ 50%.

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Section: Methods For Calculating Snrmentioning

confidence: 99%

Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.² on a Bit-Patterned Medium

Akagi

Ushiyama

Miyamoto

et al. 2012

Jpn. J. Appl. Phys.

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“…This field is usually calculated by 2D models limited to ideal shields having infinite permeability (Yuan and Bertram, 1993). For 3D heads with arbitrar permeability, large‐scale finite element method (FEM) computation could be used (Suzuki and Ishikawa, 1998). Because the MR reading heads for disk/tape drives discussed here are systems with very different dimensions, the BEM seems the most adapted.…”

Section: Model Descriptionmentioning

confidence: 99%

3D micromagnetism‐magnetostatic coupling technique for MR reading heads modeling

Firastrau

Buda-Prejbeanu

Toussaint

et al. 2008

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

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PurposeThe purpose of this paper is to develop an original approach to simulate the reading process for multitrack shielded magneto‐resistive reading (MR) heads.Design/methodology/approachThe shields and the media are of micron size while the sensor has sizes comparable with the characteristic length scales of the magnetic materials which are of the order of nanometer. Because of this large difference of scales between the different parts of the head, the macroscopic shields and the media are described by a boundary element method (BEM) approach, while the sensor is treated by micromagnetism in order to reconstruct the response of shielded multitrack MR head. To select the most favorable approach, several releases were implemented and compared. A technique based on a full‐coupling procedure was found to be the most general but too expensive in time. Appling the perfect‐imaging method directly into the micromagnetic simulator, the authors succeed in accelerating the computation without loosing accuracy.FindingsSolving by BEM the Poisson equation for the scalar magnetic potential only the surfaces interfaces are discretised, saving thus computation time and memory resources. In addition, for multi‐tracks data pattern, the magnetic scalar potential may be estimated with a good approximation by considering a periodic system along the crosstrack direction. By applying the Fourier series expansion for the magnetic charges distribution along the crosstrack direction, the initial BEM 3D problem can be treated as a bi‐dimensional one.Originality/valueThis macroscopic‐microscopic coupling technique allows a full description of the behaviour of the magnetic sensor in its environment, being a useful tool for the design and the optimisation of the multitrack MR reading heads.

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“…The large discrepancy in characteristic length scales of the various head elements results in complex computational issues. Indeed, the medium field is usually calculated by bi-dimensional (2D) models limited to shields with infinite permeability [1][2][3] or by large scale finite element method (FEM) computation with arbitrary permeability (2D/finite 3D) [4]. Inversely, the sensor response has to be described in a micromagnetic approach which is impossible to implement above the micron-scale to limit computation time.…”

mentioning

confidence: 99%

Boundary element method and micromagnetism coupling for magneto-resistive heads modeling

Firastrau

Buda

Toussaint

et al. 2004

Journal of Magnetism and Magnetic Materials

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A new method of calculating the medium field and the demagnetizing field for MR heads

Cited by 19 publications

References 4 publications

Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.² on a Bit-Patterned Medium

Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.² on a Bit-Patterned Medium

3D micromagnetism‐magnetostatic coupling technique for MR reading heads modeling

Boundary element method and micromagnetism coupling for magneto-resistive heads modeling

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A new method of calculating the medium field and the demagnetizing field for MR heads

Cited by 19 publications

References 4 publications

Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.2 on a Bit-Patterned Medium

Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.2 on a Bit-Patterned Medium

3D micromagnetism‐magnetostatic coupling technique for MR reading heads modeling

Boundary element method and micromagnetism coupling for magneto-resistive heads modeling

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Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.² on a Bit-Patterned Medium

Read-head Conditions for Obtaining Areal Recording Density of 5.8 Tbit/in.² on a Bit-Patterned Medium