Lattice Dynamics and Normal Coordinate Analysis of HTSC TlCa3Ba2Cu4O11

Abstract

For the Basic understanding of physical properties such as thermal, Elastic infrared etc., it is indispensable to have the knowledge of phonon frequency spectrum which can be achieved by means of theoretical model of Lattice dynamics and Normal Coordinate analysis.    The lattice dynamics of the high temperature superconductors TlCa₃Ba₂Cu₄O₁₁ has been investigated on the basis of the three body force shell model (TSM).  The various interactions between ions are treated on a general way without making them numerically equal.  The phonon frequency at the zone centre of Brillouin  zone are presented and the vibrational assignments are discussed.  Further the normal coordinate calculation has also been employed to study the vibrational analysis of this compound.  The normal coordinate analysis of the superconductor TlCa₃Ba₂Cu₄O₁₁ has been calculated by using Wilson’s F-G matrix method which is useful for the confirmation of our present investigation.  The vibrational frequencies and the potential energy distribution (PED) of the optically active phonon modes are also presented.

Keywords: Lattice dynamics , Normal coordinate analysis, Infrared spectroscopy, Raman spectroscopy, Zero wave vector, High temperature superconductor TlCa₃Ba₂Cu₄O_11.