Raman spectroscopy of the superconductor CuCrO2 delafossite oxide

Polycrystalline CuCrO2 samples were successfully prepared by traditional solid-state reaction method and using self-combustion urea nitrate process. The crystal structure and the effect of the sample preparation on the Raman vibrational modes were systematically investigated. Raman spectra at room temperature were obtained with light focused on several points inside a single grain. Phonon modes allowed by symmetry were identified, besides of some additional lines. Significant differences in phonon modes between samples prepared by solid state reaction method and self-combustion urea nitrate process were observed.