Alkali, Chalcogen, Nonmetal, Real part of permittivity, Tetragonal

• As-H-K-N-O
• As-H-K-O
• Bi-Na-O-Ti
• Ba-F-K-O-Ti
• Ba-Bi-Na-O-Ti
• nonmetal
• chalcogen
• alkali
• ferroelectric
• disordered