Effect of Damping on the Time Variation of Fields Produced by a Small Pole Tip With a Soft Under Layer

Abstract

ReuseUnless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. Abstract-The time variation of magnetostatic fields generated by space and time varying magnetization configurations in small perpendicular pole tips is studied. The magnetization configurations are a response to external fields driving the pole tip and soft under layer (SUL). When the system damping is sufficiently small the magnetization excitations persist for a long time after reversal. The effects of damping parameter, position in the media, and discretization cell size on the magnitude of the time varying magnetostatic fields will be given. Decreasing the damping parameter increases the magnitude of the magnetostatic field variation.

Read and write processes, and head technology for perpendicular recording

“…Micromagnetic simulations provide the most direct approach. Recently, various groups have shown results using dynamical micromagnetic models for perpendicular recording system at various scales, and have used these models to study perpendicular recording physics and to propose new designs of recording heads and media [54][55][56][57][58][59]. Note that because of the large memory required for calculating the magnetostatic interactions and small cell size required for resolve the magnetization dynamics in the medium and near the writer pole tip, this approach has only very recently become practical.…”

Finite-Temperature Simulations for Magnetic Nanostructures

“…Although this value is approximately an order of magnitude larger than the value obtained experimentally using Ferromagnetic Resonance (FMR), it has been noted that the FMR value is for small deviations of the magnetization from equilibrium and is not representative of the large deviations which occur during reversal 21 . In general, care should be taken in establishing an appropriate damping parameter to use in simulating a particular magnetic nanostructure, as also illustrated in other recent micromagnetic studies 22,23,24 .…”