Phonon Frequency Spectrum through Lattice Dynamics and Normal Coordinate Analysis of HTSC Tl2Ca3Ba2Cu4O12

Abstract

The lattice dynamics of the high temperature superconductors Tl₂Ca₃Ba₂Cu₄O₁₂ 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 Brillouin  zone 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, Brillouin zone, Three shell Force shell Model, Tl2Ca3Ba2Cu4O12, Zero Wave Vector, high-temperature superconductors, Raman, infrared. Phonon Frequency ,etc.