Large critical current density in MgB₂wire using MgB₄as precursor

Abstract

A high-purity MgB 4 phase has been synthesized and used as the precursor powder for the realization of in situ wires. Various final heat treatments, from 550 to 1100 • C for 20 min each, have been carried out to convert the inner mixture to MgB 2 . Critical current densities up to 1.75 × 10 6 and 0.98 × 10 6 A cm −2 at 4.2 and 20 K, with 0.2 T, up to 0.76 × 10 5 A cm −2 at 4.2 K and 4 T, and up to 0.78 × 10 5 A cm −2 at 20 K and 2 T were measured. Critical temperatures up to 38.5 K were measured. These results suggest that this could be a good alternative to both ex situ and classical in situ routes.

Enhanced critical current density of in situ processed MgB2 bulk superconductors with MgB4 additions

“…The detailed preparation condition of MgB 4 was well described in previous reports [33][34][35][36][37][38]. The impurity phases included in the synthesized MgB 4 powder were removed by the HNO 3 leaching process [36].…”

Nano-sized boron synthesis process towards the large scale production

“…The procedure was already described in reference [12]. Synthesis of MgB 2 was done after the deformation process at 800°C for 1 h under Ar flow.…”

Effects of heat treatment temperature on the formation of MgB2 bulk superconductors prepared using MgB4 and Mg powder

“…Recently, a new fabrication process, which can synthesize MgB 2 through a reaction between MgB 4 and Mg has been developed [16][17][18][19][20][21]. In this process, instead of Mg and B powders, MgB 4 and Mg powders are used as raw materials to increase the sintered density of MgB 2 .…”