Dissertation/Thesis Abstract

An efficient algorithm for calculating fluctuation field and simulating the thermal magnetic aftereffect
by Chen, Andrew Peijie, Ph.D., The George Washington University, 2008, 130; 3341358
Abstract (Summary)

As storage media density continues to increase, research and development in the area of ultrathin films and multilayer media has increased. Correspondingly, the thermal magnetic aftereffect, which is caused by reversing the magnetic domain over time and is an important factor in placing limits on the achievable recordable density in recording media, has become a significant topic of research [BER01] [HOL00] [GRA93] [SBI00].

My research seeks to simulate the aftereffect in experimental bimodal CoPt media and calculate its magnetic properties. The Preisach-Arrhenius Model is modified in the following way: adding multilayer parameters, the Moving model and Variable-Variance model and calculating the Preisach plane using a Cobweb grid. The Co/Pt multilayer media is simulated and compared with experimental hysteresis and aftereffect curves. Good agreement between the experimental results with the simulation program was obtained. We further proved there are two kinds of magnetic phases in the Co/Pt multilayer, and that each phase is characterized by its own magnetic properties. After simulation and calculation most magnetic properties of the material were obtained.

In this research, we develop an efficient and realistic computer model to calculate the magnetic fluctuation field. To test this, we generated artificial data files, with and without noise to simulate the experimental hysteresis loop and the thermal magnetic aftereffect. These data files are then used by the program to calculate the influence of different parameters on the accuracy of aftereffect measurement and fluctuation field calculation.

Indexing (document details)
Advisor: Torre, Edward Della, Bennett, Lawrence
Commitee: Carroll, Robert, Davies, Joseph, Zaghloul, Mona
School: The George Washington University
Department: Electrical Engineering
School Location: United States -- District of Columbia
Source: DAI-B 69/12, Dissertation Abstracts International
Subjects: Electrical engineering, Electromagnetics
Keywords: Computer algorithm, Fluctuation fields, Thermal magnetic aftereffects
Publication Number: 3341358
ISBN: 9780549963912
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