High Tc Superconductivities of A2Ba4Cu6O14+y

Superconductivities of A22Ba44Cu6O14+y (0<y<2.5, A = lanthanides except for Pm) compounds are studied through X-ray powder diffraction pattern analysis and electrical resistance measurement. Resultant compounds in case of A = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm and Yb except for Ce, Pr, Tb and Lu exhibit both characteristic diffraction patterns for A2Ba4Cu6O14+y , i.e., oxygen defect perovskite (GDP) and superconducting state. Key structure for realizing high Tc more than 90 K and narrow transition width is confirmed to be related with the GDP phase.