Two-dimensional models of the read head are not suitable for simulating the replay
of the extremely high density data that is expected to be achieved in hard drives
using perpendicular recording. By matching a singular function approximation to the
Fourier solution at the air-bearing surface (ABS), a three-dimensional analytic model
of a shielded giant magnetoresistive head, with side shields, for perpendicular replay is
derived in this thesis. An explicit expression for the potential in the ABS is presented
and parameters in that expression are accurately estimated for a range of practical
head dimensions. Using only a few terms of this singular potential model, the vertical
field is accurate to within 2% of the sensor potential in the region of the medium for
the majority of head dimensions suitable for magnetic recording.
The expected increase in areal density in hard drives using perpendicular technology
will require very narrow t racks which normally suffer from large inter-track interference
(ITI) or crosstalk. This interference can corrupt the read data and reduce t he signal
strength. Here, the effects of ITI across three tracks in a three-head system are modelled
by applying the three-dimensional singular function model of the head field. The
magnetisation patterns which cause the worst ITI are identified so that these codes
can be prohibited. A coding constraints scheme, in which ITI is exploited to read from
tracks which have widths that are just 70% of the width of the head, is presented.
Date of Award | 2008 |
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Original language | English |
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Awarding Institution | |
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A Three-Dimensional Singular Model of a Magnetic Perpendicular Recording Head with Applications to Inter-Track Interference
Jermey, P. M. (Author). 2008
Student thesis: PhD