Synthesis and properties of Mg(1−x)CuxB2 bulk obtained by self-propagating high-temperature synthesis (SHS) method at low temperature

Synthesis and properties of Mg(1−x)CuxB2 bulk samples obtained by self-propagating high-temperature synthesis (SHS) method at low temperature are presented. The best preheating temperature T0 is from 250 °C to 350 °C. We found that the part of Cu atoms may be introduced into the lattice of MgB2 to replace the Mg atoms and the other of Cu atoms forms MgCu2. The critical temperature Tc is 36.5 K in Mg0.8Cu0.2B2 and the width of transition is less than 0.3 K. The Mg0.8Cu0.2B2 sample shows the highest Jc of 6.7 × 105 A/cm2 under 0.5 T (Tesla) at 10 K and 5.0 × 105 A/cm2 in self-field at 20 K. The significant enhancement of Jc in Cu-doped samples may be caused by good grain connection, the reduction of grain size and small MgCu2 particles in the sample. This technique has a great potential to prepare high performance MgB2 bulk samples and wires by Cu doping on an industrial scale.