The effect of solvent treatments and aging on the superconducting properties of MgB2 materials

To examine the effect of solvent treatments on the superconducting properties of MgB2, solvent-treated MgB2 powders were prepared by mixing with water, acetone, or ethanol. No degradation of the superconductivity of MgB2 by the acetone or ethanol treatments was observed. Appreciable change which accompanies degradation of superconducting properties was observed only when MgB2 was mixed with water. In addition, to investigate the variation of the flux pinning effect due to the aging, the Ag8-MgB2, (SiC)4-MgB2, and sintered pure-MgB2 pellets were kept at room temperature for two and half years in air. The aged Ag8-MgB2 composite superconductor has showed degradation of flux pinning effect. The in-field superconducting properties of (SiC)4-MgB2, however, did not change after aging