Chalcogen, Conductor, Transitional, Optical properties, Tetragonal

• O-Ti
• Ba-O-Ti
• Cu-La-O-Sr
• Ba-Cu-O-Y
• Cu-La-O
• phonons
• optical spectra
• optical absorption
• Raman spectra
• wavenumber of optical phonon
• transitional
• conductor
• chalcogen
• semiconductor
• disordered