Effects of Fe substitution on the transport properties of the superconductor MgB2

Gahtori, Bhasker and Lal, Ratan and Agarwal, S. K. and Kuo, Y. K. and Sivakumar, K. M. and Hsu, J. K. and Lin, J. Y. and Rao, Ashok and Chen, Soo Kien and MacManus Driscoll, Judith L. (2007) Effects of Fe substitution on the transport properties of the superconductor MgB2. Pysical Review B, 75 (18). ISSN 1098-0121

[img] PDF
155Kb

Official URL: http://dx.doi.org/10.1103/PhysRevB.75.184513

Abstract

A systematic study has been made on the effect of Fe substitution by means of resistivity, thermal conductivity, and Seebeck coefficient of the Mg1−xFexB2 superconductor involving 0%, 0.3%, 0.6%, 1.2%, and 3.0% Fe content. The superconducting transition has been found to be very sharp 0.2 K for a pristine sample and substitution of Fe results in the decrease of TC with the increase in the transition width. Thermal conductivity is found to decrease with Fe content in general, such that the shoulder present in the pristine sample tends to fade away with increasing Fe. An analysis has been made on the normal state resistivity in terms of a two-band model, and of the thermal conductivity in terms of the Wiedemann-Franz law and the lattice thermal conductivity,and the information obtained on the basis of this analysis has been discussed. Besides, the electronic density of states DOS near the Fermi level remains nearly unaffected upon Fe substitution, as evidenced by the Seebeck coefficient measurements. When compared with Mn, Fe behaves like a nonmagnetic element with a modest variation in TC and on the other hand, the TC depression is much stronger when compared with other elements like Al, Cu, etc. Therefore, the observed variation in TC for the presently investigated concentrations of Fe is attributed to the specific nature of the given substituent element Fe in altering the phonon frequency and/or electron-phonon coupling strength rather than spin-flip scattering or change in DOS or disorder.

Item Type:Article
Keyword:Fe substitution, superconductor MgB2
Faculty or Institute:Faculty of Science
Publisher:American Physical Society
DOI Number:10.1103/PhysRevB.75.184513
ID Code:7436
Deposited By: Najwani Amir Sariffudin
Deposited On:28 Jun 2010 03:24
Last Modified:27 May 2013 07:35

Repository Staff Only: item control page

Document Download Statistics

This item has been downloaded for since 28 Jun 2010 03:24.

View statistics for "Effects of Fe substitution on the transport properties of the superconductor MgB2"


Universiti Putra Malaysia Institutional Repository

Universiti Putra Malaysia Institutional Repository is an on-line digital archive that serves as a central collection and storage of scientific information and research at the Universiti Putra Malaysia.

Currently, the collections deposited in the IR consists of Master and PhD theses, Master and PhD Project Report, Journal Articles, Journal Bulletins, Conference Papers, UPM News, Newspaper Cuttings, Patents and Inaugural Lectures.

As the policy of the university does not permit users to view thesis in full text, access is only given to the first 24 pages only.