Chalcogen, Diamagnetic, Intermediate valence, Karpinski, Orthorhombic

• Ba-Cu-O-Y
• Ba-Cu-Ho-O
• Ba-Cu-Er-O
• superconductivity
• structural properties
• superconducting transition temperature
• electronic and electrical properties
• values of superconducting transition temperature
• alkaline
• diamagnetic
• chalcogen
• conductor
• high-tc superconductor