Effects of surface-treated boron powder using chemical solvents on MgB2 bulk superconductors

MgB2 superconducting properties have been investigated with the surface-treated boron powders using the chemical solvents. Various solvents were used such as acetone, ethanol, methanol, and water to possibly modify the surface condition of raw boron powders as received. This treatment was done at an argon gas environment inside the glove box to reduce the further contamination during and after chemical treatments. It was found that Tc values were increased to 37.58-37.73 K from the pure sample of 37.50 K when they were treated in inert environment. High- fields Jc at both 5 & 20 K was all increased regardless of any kinds of chemical treatments mentioned above. It is also noted that the Jc at low-fields were increased in the order of solvents: ethanol > acetone > pure MgB2 = methanol > water.