Structure of MgB2 Ceramics Synthesized with Excess of Magnesium after Cold Deformation and Annealing

Abstract

Abstract—In a bulk MgB₂ compound synthesized with an excess of magnesium, a structure that could provide high critical currents has been obtained as a result of deformation by upsetting and subsequent annealing at 650°C for 7 h. The investigation of this structure using X-ray diffraction and scanning and transmission electron microscopy methods has shown that a dense nanosized matrix MgB₂ phase with good intergrain bonding is formed in the obtained material. In the matrix phase, there are uniformly distributed dispersed inclusions of MgO, which could serve as pinning centers.