Tube filling technique influence on superconductivity in MgB2-based conductors prepared using laboratory made boron

TL;DR

This study systematically examines how different filling techniques and heat treatments affect the superconducting properties of MgB2-based wires made with laboratory-synthesized boron, focusing on critical current density and temperature.

Contribution

It provides a detailed comparison of filling techniques and heat treatments on superconducting properties of MgB2 wires using laboratory-made boron.

Findings

Filling technique influences critical current density.

Heat treatment temperature affects critical temperature.

Laboratory synthesis of boron yields high-quality MgB2 conductors.

Abstract

Here we report a systematic study of superconductive properties of mono-filamentary MgB2-based wires, manufactured with different filling technique. A detailed comparison of the influence of filling technique and final heat treatment on superconducting properties has been given. Boron used was synthesized in laboratory following magnesiothermic reduction of boron oxide, purified thanks to several acid leaching and heat treated at high temperature, to enhance crystalline degree. Critical current density and critical temperature have been investigated at different synthesis/sintering temperature in order to evaluate their dependence to applied final heat treatment. Critical current density has been evaluated on short wire pieces by magnetic measurement in a MPMS 5.5T Quantum Design SQUID, while critical temperature has been measured with a four probe system, by the drop of resistivity during the cooling of the sample in a liquid helium dewar.