Antiferroelectric, Chalcogen, Optical properties, Trigonal

• Bi-Fe-O
• Bi-Na-O-Ti
• Ba-O-Ti
• B-Ge-La-O
• Bi-Fe-O-Y
• phonons
• Raman spectra
• wavenumber of optical phonon
• optical spectra
• luminescence
• antiferroelectric
• chalcogen
• transitional
• ferroelectric
• nonmetal