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 MgB 2 , solvent-treated MgB 2 powders were prepared by mixing with water, acetone, or ethanol. No degradation of the superconductivity of MgB 2 by the acetone or ethanol treatments was observed. Appreciable change which accompanies degradation of superconducting properties was observed only when MgB 2 was mixed with water. In addition, to investigate the variation of the flux pinning effect due to the aging, the Ag 8 –MgB 2 , (SiC) 4 –MgB 2 , and sintered pure-MgB 2 pellets were kept at room temperature for two and half years in air. The aged Ag 8 –MgB 2 composite superconductor has showed degradation of flux pinning effect. The in-field superconducting properties of (SiC) 4 –MgB 2 , however, did not change after aging.