Chalcogen, Khan, Optical properties, Tetragonal

• Ba-Ca-Cu-O-Tl
• Bi-Eu-O-Sm-V-Y
• Eu-O-Sm-V-Y
• Ba-Be-Ca-Cu-O-Tl
• O-Sm-V-Y
• phonons
• luminescence
• optical absorption
• infrared spectra
• chalcogen
• transitional
• alkaline
• oxide
• conductor