The enhancement of critical current density of powder-in-tube processed MgB2 tapes by pre-heating of Mg and B mixed powder

Abstract

MgB2 tapes were fabricated by a powder-in-tube method using a powder mixture of Mg and B pre-heated at 400–650 ° C for 1–10 h under low oxygen partial pressure. Application of this pre-heating drastically enhanced Jc values. Fine MgO particles existed in the core of MgB2 tape prepared from the pre-heated powder. These MgO particles were formed by the reaction of B2O3 on the surface of B particles with Mg powder. The excellent Jc values can be attributed to both the flux pinning of these fine MgO and the increase of MgB2 volume fraction in the tapes.