Optical phonons in new ordered perovskite Sr2Cu(Re0.69Ca0.31) Oy system observed by infrared reflectance spectroscopy

TL;DR

This study investigates the infrared reflectivity spectra of a new ordered perovskite Sr2Cu(Re0.69Ca0.31)Oy, revealing optical phonon behavior and temperature-dependent lattice dynamics in a correlated cupric oxide system.

Contribution

It provides the first detailed analysis of optical phonons in this novel perovskite using infrared spectroscopy and Lorentz oscillator modeling.

Findings

Identification of multiple optical phonons in the spectrum.

Observation of large residual bands at 315 and 653 cm-1.

Temperature dependence of phonon energy and damping factors.

Abstract

We report infrared reflectivity spectra for a new correlated cupric oxide system Sr2Cu(Re0.69Ca0.31)Oy with y ~ 0.6 at several temperatures ranging between 8 and 380 K. The reflectivity spectrum at 300 K comprises of several optical phonons. A couple of residual bands located around 315 and 653 cm-1 exhibit exceptionally large intensity as compared to the other ones. The overall reflectivity spectrum lifts up slightly with increasing temperature. The energy and damping factor of transverse-optical phonons are determined by fitting the imaginary dielectric constant by Lorentz oscillator model and discussed as a function of temperature in terms of lattice anharmonicity.