Raman and Infrared Vibrational Spectra of PbGa2S4 Crystal
Technical University of Moldova, 168 Stefan cel Mare Avenue, 2004 Chisinau, Republic of Moldova 2
Institute of Applied Physics, Academy of Sciences of Moldova, 5 Academy Street
2028 Chisinau, Republic of Moldova
N.N. Syrbu, V.V. Zalamai, ”Raman and Infrared Vibrational Spectra of PbGa2
S4 Crystal”, American
Research Journal of Materials Science, vol 1, no. 1, pp. 1-9
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.
