Accurate approximation of fields and spectral response functions for perpendicular recording heads

Wilton, D.T.; Shute, H.A.; Mapps, D.J.

doi:10.1109/20.774190

Cited by 12 publications

(9 citation statements)

References 24 publications

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“…6 to represent the gap region of a general magnetic head (in region 1) at close proximity d to a SUL beyond the head surface (region 2). The geometry of this model is similar to the 'slot' approximation proposed in [22] for the symmetrical ring-head, but generalised here to model any gapped head structure using the integral transform approach. To simplify the mathematical development and to a very good approximation for small head-to-underlayer separations, the potential on either side of the gap corners is assumed to vary linearly between the head and underlayer, and vanishes at the SUL surface (y = d) as indicated in Fig.…”

Section: B With Underlayermentioning

confidence: 99%

“…The field expressions in (22) account for the infinite reflections of the magnetic fields between the high permeability head surface and underlayer [21], and the effect of the gap and the reaction of the underlayer on the surface field are included in the surface field ) 0 , (x H r x . For the asymmetrical head considered here, the surface field ) 0 , (x H r x can be derived from the gradient of the potential in (9) (or equally (10)).…”

Section: B With Underlayermentioning

confidence: 99%

“…It is possible to integrate (22) exactly using the surface field distribution in (23), however the solution is intractable and in terms of the hypergeometric series function. The magnetic fields in (22) can be numerically evaluated more conveniently and quickly using the inverse Fast Fourier Transform from equations (21). Alternatively, and in this article, the fields in (22) were more easily integrated numerically over the gap length using the surface field in (23).…”

Section: B With Underlayermentioning

confidence: 99%

“…The magnetic fields in (22) can be numerically evaluated more conveniently and quickly using the inverse Fast Fourier Transform from equations (21). Alternatively, and in this article, the fields in (22) were more easily integrated numerically over the gap length using the surface field in (23). (22) and using the surface field distribution from (23).…”

Section: B With Underlayermentioning

confidence: 99%

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Approximate Expressions for the Magnetic Potential and Fields of 2-D, Asymmetrical Magnetic Recording Heads

2016

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Two-dimensional asymmetrical magnetic head are characterised by parallel inclination of the semi-infinite, inner gap walls, and where the gap length and head-to-underlayer separation are small compared to the other dimensions in the head. With head corner inclination, these structures contribute to reduction in the effective gap length of the head and therefore increase in the field magnitude and narrowing of the field distributions near the acute gap corner. Asymmetrical heads were therefore proposed for increasing the writing and readout resolutions in gapped magnetic head structures. There are currently no explicit or approximate analytical solutions for the potential and fields from two-dimensional asymmetrical magnetic heads. This paper is concerned with the detailed theoretical derivation of relatively simple closed-form approximations for the scalar magnetic potential and fields from twodimensional asymmetrical magnetic heads and their Fourier transforms, applicable to any arbitrary corner inclination angle. A general theory based on the translated Sine Fourier series is developed to model and study the reaction of a soft magnetic underlayer (SUL) on the surface potential of any magnetic head structure, and applied to the asymmetrical head. The approximate potential and field expressions derived in this paper demonstrated very good agreement with finite-element calculations of two-dimensional asymmetrical heads.

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Section: B With Underlayermentioning

confidence: 99%

Section: B With Underlayermentioning

confidence: 99%

Section: B With Underlayermentioning

confidence: 99%

Section: B With Underlayermentioning

confidence: 99%

See 2 more Smart Citations

Approximate Expressions for the Magnetic Potential and Fields of 2-D, Asymmetrical Magnetic Recording Heads

2016

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“…A number of approaches for generating increasingly accurate and fast approximations have been developed [4]- [8]. These have included configurations for perpendicular recording, where a soft underlayer is included [9]- [11]. However, this prior work has tended to describe relatively simple configurations with isotropic permeability and a minimum of layers: for example, longitudinal media with no soft underlayer or perpendicular media with an ideal soft underlayer.…”

Section: Introductionmentioning

confidence: 98%

Readback Responses for Complex Recording Media Configurations

Wilton

Wood

2004

IEEE Trans. Magn.

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This paper describes a relatively simple approach to calculating the frequency response for a two-dimensional (2-D) magnetic recording system with a medium that can include an arbitrary number of layers. Each layer may have an arbitrary magnetization direction, anisotropic permeability, and exchange coupling. The approach relies on an initial transformation into the spatial frequency domain and then the use of transmission matrices to relate the fields in the different layers. The approach is general in that it provides a method for finding the field configuration for any set of 2-D magnetic sources embedded in a layered magnetic medium with a linear -relationship. Here, we focus on calculating the readback response for a variety of longitudinal and perpendicular recording configurations. Since the permeability may have any wavelength dependence, we can easily include the effect of exchange coupling in the underlayer.

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