Delafossite CuFeO2has recently attracted considerable attention because of its complex phase transitions and practical applications. A thorough understanding of the optical properties of CuFeO2is essential for its further exploration. In this paper, we investigated the temperature-dependent optical properties of CuFeO2single crystals through Raman scattering spectroscopy and spectroscopic ellipsometry. The room temperature Raman scattering spectrum exhibited six phonon modes at approximately 352, 509, 692, 1000, 1052, and 1171 cm−1. Upon cooling across 11 K, which is the rhombohedral to monoclinic structural phase transition temperature, a softening of theEg-symmetry 352 cm−1mode and a hardening of theA1g-symmetry 692 cm−1mode were observed. Moreover, analysis of the temperature-dependent real part of the dielectric function and direct band gap revealed anomalies at 11 K. These results demonstrate a profound connection between the structural phase transition, lattice dynamics, and electronic structure of CuFeO2and provide key information for CuFeO2-based device design and fabrication.
ASJC Scopus subject areas
- Chemical Engineering(all)