| 摘要 |
A method of preparing a superconducting magnesium diboride powder is provided to produce a wire having high critical current density by increasing the number of grain boundaries that can fixate magnetic flux, increase the number of filaments during manufacturing of a superconducting multi-core wire, increase mechanical processing characteristics of a superconducting magnesium diboride wire, and increase engineering critical current density of the superconducting magnesium diboride wire. A method of preparing a superconducting magnesium diboride powder includes the steps of: mixing 2 moles of an aqueous boracic acid solution with 1.0 to 1.5 mole of an aqueous solution comprising magnesium metal ions, and heating and stirring the mixed solution at 25 to 100 deg.C for 0.5 to 10 hours to prepare an aqueous solution in which magnesium and boracic acid metal ions are mixed; adding ethyl alcohol to the aqueous solution to prepare a precursor solution having a concentration of 0.05 to 2.0 mol/L; and spraying the precursor solution by a spray and heat-treating the sprayed precursor solution in a thermal reactor to prepare a superconducting powder, wherein the aqueous solution comprising magnesium metal ions is one selected from magnesium nitrate, magnesium acetate, and magnesium citrate. The aqueous solution preparing step includes the process of additionally adding a nano-sized SiC fine powder for performing a magnetic flux-fixating function into the aqueous solution and stirring the mixture. |
