Vibrational spectra of CaGa2O4, Ca2GeO4, CaIn2O4 and CaSnO3 prepared by electrospinning

CaGa2O4 nanofibers, Ca2GeO4 microfibers, CaIn2O4 nanorods, and CaSnO3 nanofibers were synthesized by using an electrospinning technique. Structures and morphologies of the as-synthesized oxides were characterized by X-ray diffraction and scanning electron microscopy, respectively. Raman and infrared spectra were also recorded and analyzed at room temperature. More significantly, nuclear site group analysis was carried out and the number of normal vibrational modes, Raman-active, and infrared-active optical phonon modes were obtained by theoretical calculation. Finally, vibrational assignments of the observed Raman peaks and infrared absorption bands were given based on the group theoretical analysis and experimental data from literature.