Far-infrared optical properties of YVO 4 single crystal

Near-normal incident infrared reflectivity spectra of a (001) YVO 4 single crystal have been measured at different temperatures in the frequency region between 100 and 6000 cm -1 . The reflectivity spectra are analyzed with the factorized form of the dielectric function, and the dielectric properties and optical conductivity of the YVO 4 crystal are obtained. From the TO/LO splitting, effective charges at different temperatures are calculated to study the ionicity of YVO 4. The internal modes of the VO 4 3- ion and the external modes of the Y(VO 4) lattice are compared with SiO 4 4- in zircon and with other rare-earth vanadates. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 200677.22.Ch Permittivity (dielectric function), 78.20.-e Optical properties of bulk materials and thin films, 63.20.-e Phonons in crystal lattices ,