SUPERCONDUCTIVITY OF (TI_1-xAl_x) ₂Ba₂ Ca₂Cu₃O_y

The structure, magnetic, and superconducting properties of the (TI_1-xAl_x) ₂Ba₂ Ca₂Cu₃O_y with x=0.05, 0.1, 0.15, 0.2 were studied. The T_c ^R=0 depends on whether the sample has a 2223 phase structure or has a 2212 phase structure. The magnetic properties in low field were measured and discussed.