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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/3662

Title: STUDY OF MAGNETIZATION AND CRITICAL TEMPERATURE FOR NANOMAGNETIC PARTICLES
Authors: ABRHAM, FESEHA
Advisors: Prof. P.Singh
Keywords: Magnetic nanostructure
nanowires
Copyright: Jun-2011
Date Added: 6-Nov-2012
Publisher: AAU
Abstract: Magnetic nanostructures, such as dots and dot arrays, nanowires, multilayers and nano- junctions, are reviewed and compared with bulk magnets. By using the Gibbs free energy variational principle based on the Bogoliubov inequality the magnetic properties and crit- ical behavior of metallic nanoparticles having concurrently atomic disorder, dilution and competing interactions, are studied within the framework of an Ising model. As a case of study we have considered the Fe0:5Mn0:1Al0:4 alloy characterized for exhibiting, un- der bulk conditions, low temperature reentrant spin glass (RSG) behavior and for which experimental and simulation results are available. Our results allow concluding that the variational model is successful in reproducing features of the dependence of the critical temperature with particle size and low temperature magnetization reduction consistent with a RSG behavior. In this work we compute the magnetization per site and the mag- netic susceptibility, as a function of temperature, for di erent values of the coordination number. vi
Description: A THESIS PRESENTED TO THE SCHOOL OF GRADUATE STUDIES ADDIS ABABA UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN PHYSICS
URI: http://hdl.handle.net/123456789/3662
Appears in:Thesis - Physics

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