Enhanced superconducting properties of Eu2O3-doped MgB2

Bulk polycrystalline samples of Eu2O3-doped MgB2 have been synthesized by a standard solid state reaction route and their structural and superconducting properties have been investigated. As a function of Eu2O3 content we have found a significant increase in the critical current density (J(c)) and the irreversibility field (H-irr) in the magnetic field range 0-6 T. The XRD results reveal the presence of MgO and EuB6 secondary phases along with the main hexagonal phase of MgB2. The strain values and the lattice distortions have been found to increase almost linearly with the nominal Eu2O3 content. The observed significant improvement in J(c)(H) and H-irr in the Eu2O3-doped MgB2 samples. thus is mainly attributed to the lattice distortions introduced by Eu2O3 doping. (C) 2009 Elsevier B.V. All rights reserved.