On the superconducting transition of Nb3Al-core wires and pressed powder compacts

The superconductive transition has been investigated of various Nb3Al pressed powder compacts and core powder compacts, the latter being left after dissolving the Cu matrix from wires. Every sample was measured in the pressed respectively as drawn condition and after subsequent powderization. The superconducting transition was determined inductively in the temperature range 6 to 18 K. The shape of the transition curves ΔUsub(c)(T) is discussed considering mechanical stress during the drawing process or compaction