Progress in joining of melt-textured YBCO

High-pressure synthesis of pure and doped superconducting MgB2compounds

“…Shortly after the discovery of superconductivity in MgB 2 , we were the first to synthesize MgB 2 in HP-HT conditions, starting directly from metallic Mg and B powders [10]. Since then, other groups have prepared similar samples [13][14][15]. The method consists of a reaction between liquid magnesium and solid boron at HP-HT.…”

“…For over 40 years, magnesium has been used as a catalyst for the transformation of hexagonal boron nitride (BN) to its cubic form at high pressure-high temperature (HP-HT) [6][7][8]; during this HP-HT treatment the formation of secondary MgB 6 and MgB 2 phases was observed [9]. Recently, the HP-HT method has been applied to MgB 2 for its sintering [10][11][12], its synthesis [10,[13][14][15] and its single crystal growth [16][17][18]. This paper deals with the HP-HT sintering of MgB 2 , its HP-HT synthesis and the HP-HT preparation of doped (Mg 1−x A x )B 2 compounds with A = Al, Zn, Cu, Ag, Na, Ca.…”

Effect of various mechanical deformation processes on critical current density and microstructure in MgB2tapes and wires

“…This is mainly due to the density decrease as a consequence of the phase transformation from Mg + 2B → MgB 2 . The MgB 2 density was shown to be higher after sintering of the bulk samples while a high pressure was applied [9][10][11][12][13]. The higher density of the material immediately resulted in higher critical current densities compared to the samples prepared at ambient pressure [9][10][11][12][13].…”

“…The MgB 2 density was shown to be higher after sintering of the bulk samples while a high pressure was applied [9][10][11][12][13]. The higher density of the material immediately resulted in higher critical current densities compared to the samples prepared at ambient pressure [9][10][11][12][13]. However, it is not viable to use this high-pressure sintering approach in the fabrication of long wires for practical needs.…”