Raman and Infrared Vibrational Spectra of PbGa2S4 Crystal
Abstract
Raman scattering spectrain different geometries at temperatures 10 - 300 K and infrared vibrational
spectra in polarizations E||c and E⊥c for range 50 - 4000 cm-1 at 300 K were investigated for PbGa2
Se crystals.
Contours of reflection spectra in polarizations E||c and E⊥c were calculated and parameters of phonons and
dielectric constants were determined. Temperature dependences of Raman spectra were investigated and
soft modes with different temperature dependences in intervals 80 - 150 and 150 - 370 K were discovered. A
group of lines attributed to Davydovmultiplets was found out and their polarization dependences temperature
changes were investigated. Effective ion charges were calculated and a polarizability of ionic charges of Pb, Ga
and S in PbGa2
S4
lattice was determined.
