AAU-ETD AAU-ETD
 

Addis Ababa University Libraries Electronic Thesis and Dissertations: AAU-ETD! >
Faculty of Journalism and Communications >
Thesis - Journalism and Communication >

Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/89

Title: THE STUDY OF UPPER CRITICAL FIELD CALCULETION OF SUPERCONDUCTING MAGNESIUM DIBORAIDE
Authors: Habte, Dulla
Date Added: 6-Sep-2007
Abstract: Magnesium diboride(MgB2) has joined the class of high Tc superconductors following the discovery of superconductivity in this compound in 2001 below Tc  40k. A large part of the excitement is due to the vast amount of unusual properties originating from the involvement in superconductivity of two sets of bands that are of a very different nature. Because of the different dimensionality of the two sets of bands,this”two band superconductivity” leads to a complex behavior of the anisotropic superconducting state properties as a function of magnetic field and temperature. The purpose of this thesis is to study the upper critical field (Hc2) of two-band s-wave superconducting magnesium diboride(MgB2) in the vicinity of Tc using a two-band Ginzburg-Landau(GL) theory. The analytical formula of Hc2(T) involving anisotropy of order parameter and anisotropy of effective-mass are found. The parameters of the upper critical field in ab-plane(Hab c2 ) and c-axis (Hc c2) can be found by fitting to the experimental data. In addition to this we have considered the linearized two band Eilenberger equations to calculate the upper critical field of superconducting magnesium diboride. Finally by taking the ratio of the upper critical field ( the fields in ab-plane and c-axis) we tried to show the anisotropy property of superconducting magnesium diboride. We observe that the ratio of the two fields strongly depends on temperature. So, this ratio of upper critical field is in the range of experimental result and temperature dependent. Key words: S-wave superconductor,anisotropy two-band superconductors,Ginzburg-Landau approach,Eilenberger equations,Magnesium diboride.
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/123456789/89
Appears in:Thesis - Physics

Files in This Item:

File Description SizeFormat
Habte Dulla.pdf447.99 kBAdobe PDFView/Open

Items in the AAUL Digital Library are protected by copyright, with all rights reserved, unless otherwise indicated.

 

  Last updated: May 2010. Copyright © Addis Ababa University Libraries - Feedback