IR specular reflectance spectra of KHSO4 single crystal—Dispersion analysis

Polarized specular reflectance IR spectroscopy was used to provide answers regarding dielectric, vibrational and optical properties of the KHSO₄ single crystal. Applying this technique, spectra with polarization along the principal dielectric axes were recorded. It is shown that reflectance IR spectra at arbitrary direction of polarization recorded from one of the principal planes can be easily calculated if the reflectance spectra along the corresponding two principal axes are known. Using dispersion analysis of the reflectance spectra recorded along the principal dielectric axes and employing downhill simplex iteration method, energy loss function together with the real and imaginary parts of the complex index of refraction and the permittivity tensor were obtained. Employing this data, LO-TO splitting of the modes was further calculated. Discussion concerning the assignment of the bands and its relation to the structure is also given.