Effect of carbon doping on hydrolysis of MgB2 superconductor

Pure and carbon doped MgB2 superconductors were synthesized by solid state reaction method. The effects of hydrolysis on microstructure and superconducting properties were investigated by X-ray diffraction (XRD), Scanning Electronic Microscopy (SEM) and Physical Property Measurement System (PPMS). The results show that the hydrolysis process can be found in pure and carbon doped MgB2 samples. A part of the doped carbon went into MgB2 crystal lattice and the residue distributed at MgB2 grain boundary as the second phase particles. The stability of MgB2 in water is improved by suppressing the hydrolysis reaction from grain boundary and decreasing the hydrolysis speed by the carbon doping.