Alkali, Disordered, Transitional, Optical properties, Trigonal

• Li-Nb-O
• Li-O-Ta
• Bi-Na-O-Ti
• Co-Li-O
• Li-Mg-Nb-O
• phonons
• luminescence
• optical absorption
• Raman spectra
• wavenumber of optical phonon
• disordered
• alkali
• transitional
• chalcogen
• oxide