Structural, magnetic and electrical properties of Bi1.4La0.6Sr2CaCu2−xMnxOy compounds

► Abnormal variation of lattice parameter a emerges with increasing Mn doping level. ► CuO2 planes canting and Mn valence alteration appears with increasing Mn doping level. ► Insulating character and magnetism is coexisted in Mn-doped (Bi, La)-2212 system. ► In the condition of preserving Bi-2212 structure, Bi1.4La0.6Sr2CaCu2−xMnxOy compound has the optimal resistivity and magnetism at x = 2%, which could provide a candidate as new barrier in Josephson junction in future.