Ferromagnetic spinel CuCr2Se4 studied by Raman spectroscopy and lattice dynamics calculations

TL;DR

This study combines Raman spectroscopy and lattice dynamics calculations to analyze the phonon modes of ferromagnetic CuCr2Se4, revealing mode assignments and excitation energy effects without phonon anomalies near the Curie temperature.

Contribution

It provides a comprehensive experimental and theoretical analysis of phonon modes in CuCr2Se4, including mode assignments and excitation energy dependence, expanding understanding of its lattice dynamics.

Findings

All Raman active modes identified and assigned.

Raman line intensities vary with excitation energy.

No phonon anomalies observed near Tc.

Abstract

The lattice dynamics of the ferromagnetic spinel CuCr2Se4 (Tc = 430K) was studied experimentally by measuring the Raman spectra and theoretically by calculation of zone center phonon frequencies within a shell model. All Raman allowed modes (A1g + E_g + 3F2g) were identified and assigned to specific atomic motions. The relative intensity of the Raman lines varies strongly with excitation photon energy between 1.58 and 2.71 eV, but no significant phonon anomalies are observed near Tc.