Title: Theoretical studies on phonon spectra of high temperature superconductor YBaCuFeO5

Authors: A. Punitha; Sujin P. Jose; S. Mohan

Addresses: Department of Electronics and Communication Engineering, Vickram College of Engineering, Enathi – 630 561, Tamil Nadu, India. ' Department of Electronics and Communication Engineering, Vickram College of Engineering, Enathi – 630 561, Tamil Nadu, India. ' Department of Mathematical and Physical Sciences, Hawassa University, P.O. Box 5, Hawassa, Ethiopia

Abstract: The role of superconductivity can be understood by the assignments of spectral features to lattice vibrations. Raman and infrared studies have contributed significantly to the explication of high Tc superconductor mechanics. In the present work, normal coordinate calculations have been carried out to study the vibrational analysis of perovskite like antiferromagnetic compound YBaCuFeO5. It is important to have knowledge of phonon frequency spectrum for the interpretation of physical properties such as thermal, elastic, infrared, etc., which can be achieved by means of theoretical models of lattice dynamics. A three-body force shell model (TBSM) which takes into account many body interactions is applied to study the lattice dynamics of high Tc superconductors YBaCuFeO5. For the interpretation of infrared and Raman spectrum, the phonon frequencies at the centre of Brillouin zone are presented and vibrational assignments are discussed. The calculations yield not only the phonon frequencies at the centre, but also throughout the Brillouin zone.

Keywords: normal coordinate analysis; high temperature superconductors; phonon frequencies; YBaCuFeO5; three-body force shell model; TBSM; lattice dynamics; superconductivity; perovskite; lattice vibrations.

DOI: 10.1504/IJMATEI.2012.044449

International Journal of Materials Engineering Innovation, 2012 Vol.3 No.1, pp.50 - 58

Received: 03 Jul 2010
Accepted: 16 Feb 2011

Published online: 25 Dec 2011 *

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