RAMAN, INFRARED AND OPTICAL-SPECTRA OF THE SPIN-PEIERLS COMPOUND NAV2O5

We have measured polarized spectra of Raman scattering, infrared and o ptical transmission of NaV2O5 single crystals above the temperature of the spin-Peierls transition T-SP = 35 K. Some of the far-infrared (FI R) phonon lines are strongly asymmetric, due to the spin-phonon intera ction. In addition to the phonon lines, a broad band was observed in t he c(aa)(c) over bar Raman spectrum and in the Ella FIR transmission s pectrum. A possible origin of these bands is discussed. The absorption band at 10000 cm(-1) (1.25eV) is attributed to vanadium d-d electroni c transitions while the absorption edge above 3eV is supposed to corre spond to the onset of charge-transfer transitions.