Improvement of Superconducting Joint Properties for GdBaCuO Bulk Superconductors Joined with ErBaCuO Superconductor Using Local Melt-Growth Method.

The important factors in obtaining a high-quality superconducting joint were investigated for the superconducting joint of a GdBaCuO (GdBCO) bulk superconductor with sintered ErBaCuO (ErBCO) using the local melt-growth method. REBCO (RE: rare earth) bulk superconductors can be used as strong magnets by magnetizing them, but they require large bulk sizes for their application. Although the superconducting joint presents a viable solution, many possibilities for property improvement remain, such as property degradation, depending on the joining direction.

Synthesis of Dense MgB Superconductor via In Situ and Ex Situ Spark Plasma Sintering Method.

In this study, high-density magnesium diboride (MgB) bulk superconductors were synthesized by spark plasma sintering (SPS) under pressure to improve the field dependence of the critical current density (-) in MgB bulk superconductors. We investigated the relationship between sintering conditions (temperature and time) and - using two methods, ex situ (sintering MgB synthesized powder) and in situ (reaction sintering of Mg and B powder), respectively. As a result, we found that higher density with suppressed particle growth and suppression of the formation of coarse particles of MgB and MgO were found to be effective in improving the - characteristics.