Infraredhyphen;active lattice vibrations in alkali azides

摘要

The far infrared reststrahlen spectra of lithium, sodium, potassium, rubidium, and cesium azides have been measured. The reflection spectra of monocrystalline and polycrystalline samples were analyzed by Kramersndash;Krouml;nig and damped Lorentz oscillator methods to obtain long wavelength optical mode frequencies and optical constants. It has been determined that the substances are quasicubic, which results in small anisotropy splittings. The similarity of the alkali azides with corresponding halides is pointed out.