Abstract: A process is disclosed of increasing the critical current density in a superconducting magnesium boride wire by heating a magnesium diboride precursor wire under isostatic pressure in an inert atmosphere at temperatures and for time sufficient to form a superconducting magnesium boride wire characterized as having a higher critical current density than a superconducting magnesium boride wire heated under the same temperature conditions in the absence of isostatic pressing.

Abstract: A process of preparing superconducting magnesium diboride powder by heating an admixture of solid magnesium and amorphous boron powder or pellet under an inert atmosphere in a Mg:B ratio of greater than about 0.6:1 at temperatures and for time sufficient to form said superconducting magnesium diboride. The process can further include exposure to residual oxygen at high synthesis temperatures followed by slow cooling. In the cooling process oxygen atoms dissolved into MgB2 segregated to form nanometer-sized coherent Mg(B,O) precipitates in the MgB2 matrix, which can act as flux pinning centers.