The Influence of Wire Heat Treatment on PIT MgB2 Conductors Manufactured Using Laboratory-Made Boron

In this paper, we discuss the influence of heat treat-ment (applied to the wire as sintering for ex situ wire, or synthesis for in situ wire) on critical current density of MgB2-based wires. A comparison of this influence (changing the synthesis/sintering parameters, i.e., time and temperature, applied to wire samples) for different manufacturing techniques has been given. Boron synthesized in our laboratory by magnesiothermic reduction has been used as precursor. In this paper, we show its behavior with different PIT manufacturing techniques. Different heat treatments of synthesis/sintering have been performed on short wires, to evaluate the suitable one for each manufacturing technique. Ex situ wire shows its best results in terms of Jc(105A/cm2 at 2 T) afterheat treatment at 920oC, while forin situwires a heat treatmentat 800oC was observed to be the best. A sample prepared following a mixed (ex-situ-in-situ) technique shows an independent Jc behavior from the final heat treatment. Here, we report the Jc analysis performed from transport and magnetic measurements by using Bean's model for wire samples. The transport J cof themixed sample shows the best behavior at high magnetic field, one order of magnitude higher than the ex situ wire.