Infrared lattice vibrations of PbGa2S4

Infrared reflectivity spectra of PbGa₂S₄ single crystals are measured at room temperature in the wavenumber range from 30 to 4000 cm⁻¹ for the polarization directions E ∥ c and E ∥ b. The frequencies of 13 B_1u modes and 11 B_2u modes are derived from the spectra. The results are compared with previous studies and with lattice vibration data of ternary chalcopyrite and defect-chalcopyrite compounds.