Vibrational spectroscopy of single crystals

single crystals were grown by the laser floating zone method. Polarized Raman spectra were measured and interpreted consistently with the Pcmn crystal space group. Up to 16 Raman modes were identified and their symmetry assigned. The infrared optical constants of were determined from the analysis of the reflectance spectra of single crystals and powders. In the latter case, an effective medium theory was used to analyse the reflectance spectrum. Assignment of the infrared mode symmetry was performed with the help of a theoretical calculation of the vibrational modes.