Critical Current Density, Pinning and Nanostructure of MT-YBCO and MgB 2 -based Materials

The correlations between structural features, critical current density and pinning landscape of YBa2Cu3O7-δ and MgB2-based materials produced in the forms of bulk melt-textured (MT-YBCO) and polycrystalline (MgB2) blocks and wires with excellent superconducting characteristics were revealed. The impurity oxygen distribution, higher borides inclusions and carbon doping are most important for the critical currents and pinning forces in MgB2, while the twin density and the density of Y211 inclusions are relevant in MT-YBCO.