Superconducting properties of V3Ga composite wires

Studies of the superconducting properties of V
3
Ga single filament composite wires grown by solid state reaction are presented. The three alloy compositions investigated were: V/Cu-15.4 at.% Ga, V-6.1 at.% Ga/Cu- 15.4 at.% Ga and V-9.0 at.% Ga/Cu-17.5 at.% Ga. Critical currents were measured at 4.2K in transverse magnetic fields to 175kG and transition temperature data were obtained by ac mutual inductance techniques for V
3
Ga formed at temperatures from 525°C-700°C. Growth rates for V
3
Ga were strongly influenced by alloy composition and formation temperature with more rapid growth occurring in composite wires with higher Ga contents. In addition to the more rapid growth rates obtained, a factor of 10 improvement in the critical current density (J
c
) also was exhibited in V
3
Ga grown at 600°C in the V- 9.0 at.%/Cu-17.5 at.% Ga composite specimen. The best J
c
observed to date was 10
⁶
A/cm
²
in a transverse magnetic field of 100kG for a wire reacted at 550°C.