Coexistence of Superconductivity and Ferromagnetism in Ni-Doped Bi4 −xNixO4S3 (0.075 ≤x≤ 0.150)

Abstract

The effects of Ni doping on the physical properties of the newly discovered layered superconductor Bi4O4S3 are studied. X-ray diffraction data indicates that the lattice constants a and c decrease with the increasing Ni doping. From resistivity-temperature curves, the superconducting transition temperature (\(T_{c}^{\text {onset}})\) is suppressed by only 0.5 K with the increase of Ni doping from 0.075 to 0.15; the \(T_{c}^{\text {zero}}\) is almost the same constant at different Ni ions’ doping level. The magnetic susceptibility results suggest the coexistence of superconductivity and ferromagnetism in this system. A possible superconductivity transition is observed around ˜14 K from M-T (FC) curves in x = 0.125, 0.15 samples, which may result from the doped magnetic Ni ions.