Possible coexistence of superconductivity and magnetism in intermetallic NiBi3

NiBi3 polycrystals were synthesized via a solid state method. X-ray diffraction analysis shows that the main phase present in the sample corresponds to NiBi3 in a weight fraction of 96.82 % according to the refinement of the crystalline structure. SEM - EDS and XPS analysis reveal a homogeneous composition of NiBi3, without Ni traces. The powder superconducting samples were studied by performing magnetic measurements. The superconducting transition temperature and critical magnetic fields were determined as T C = 4.05 K , H C 1 = 110 Oe and H C 2 = 3 , 620 Oe. The superconducting parameters were ξ G L = 301.5 Å , λ G L = 1549 Å , and κ = 5.136 . Isothermal measurements below the transition temperature show an anomalous behavior. Above the superconducting transition the compound presents ferromagnetic characteristics up to 750 K, well above the Ni Curie temperature.