Synthesis of superconductor MgCNi3 with carbon nanotubes

MgCNi₃, an intermetallic compound superconductor with a cubicperovskite crystal structure, has been synthesized using fine Mg andNi powders and carbon nanotubes (CNTs) as starting materials by theconventional powder metallurgy method. The composition,microstructure and superconductivity are characterized using x-raydiffraction (XRD), energy dispersive x-ray (EDX) analysis, scanningelectron microscopy (SEM), and superconducting quantum interferencedevice (SQUID) magnetometer. The results indicate that the phases ofthe synthesized samples are MgCNi₃ (major phase) and traces of Cand MgO. The MgCNi₃ particle sizes range from several hundredsof nanometres to several micrometres. The onset superconductingtransition temperature T_c of the MgCNi₃ sample is about7.2,K. The critical current density J_c is about 3.44×10⁴A/cm² calculated according to the Bean model from themagnetization hysteresis loop of the slab MgCNi₃ sample at 5Kand zero applied field.