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The effect of sample preparation parameters on magnetoresistance ratios (MR%) in CO/CU nanostructures

Lau, Yee Chen (2005) The effect of sample preparation parameters on magnetoresistance ratios (MR%) in CO/CU nanostructures. Masters thesis, Universiti Teknologi Malaysia, Faculty of Science.



The research reported in this thesis is primarily aimed at establishing the fundamental understanding of magnetoresistance (MR) phenomena occurring in layered magnetic nanostructures of Co/Cu system fabricated using sputtering and electron beam method. Emphasis is given on the studies of magnetoresistance ratios (MR%) as functions of Co layer thickness, working pressure, annealing time and temperature, number of bilayer, direction of magnetic fields, and the application of buffer layer. The Co/Cu/Co sandwiches in this study were fabricated on corning glass substrates. The electrical resistance of samples was measured using the four point Van der Pauw method when magnetic fields of ± 2500 gauss were applied. It was observed that, the MR% attained almost 10% between 2 - 6 nm of the Co layer thickness. By varying the working pressure, a maximum MR% of 11.4% was obtained at a working pressure of 2.6 x 10-3 torr. In the other hand, the MR% also increases with the increasing of annealing temperature and time. In the bilayers number, n various MR% was revealed by the existence of up-down fluctuations with the MR’s peak and valley occurring at n = 5 and n = 8, respectively. It was also observed that, the magnetic field applied in plane to the samples with and without chromium buffer layer produced higher value MR% of compared to those applied perpendicularly. Thus, the results indicate the dependent of MR% on various preparation parameters.

Item Type:Thesis (Masters)
Additional Information:Thesis (Master of Science (Physics)) - Universiti Teknologi Malaysia, 2005; Supervisor I : Assoc. Prof. Dr. Rashdi Shah Ahmad; Supervisor II : Prof. Dr. Samsudi Sakrani
Subjects:Q Science > QC Physics
ID Code:5148
Deposited By: Widya Wahid
Deposited On:31 Mar 2008 01:55
Last Modified:28 Feb 2018 07:55

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