Type: Article
Publication Date: 2002-01-09
Citations: 59
DOI: https://doi.org/10.1088/0953-2048/15/2/303
Bulk samples of MgB2 have been formed by hot isostatic pressing (HIPping) of commercial powder at 100 MPa and 950 °C. The resulting material is 100% dense with a sharp superconducting transition at 37.5 K. Microstructural studies have indicated the presence of small amounts of second phases within the material, namely MgO- and B-rich compositions, probably MgB4. Magnetization measurements performed at 20 K have revealed values of Jc = 1.3 × 106 A cm−2 at zero-field and 9.3 × 105 A cm−2 at 1 T. Magneto-optical (MO) studies have shown direct evidence for the superconducting homogeneity and strong intergranular current flow in the material.