Superconductivity in Centimeter Length Indium-Gallium Nanowires*

In-doped Ga nanowires 150 nm in diameter and 6mm in length have been formed in silica nanocapillaries. X-ray fluorescence and diffraction measurements performed at the Advanced Photon Source have been used to characterize their chemical composition and crystal structure. Investigation of the low temperature transport properties of these wires reveals a two stage superconducting transition. Magnetoresistance measurements are suggestive of vortex trapping in the wire. The X-ray fluorescence measurements suggest phase separation in the capillaries into Ga nanodroplets and In-Ga eutectic wires. A model to explain the vortex trapping consistent with this observation is being developed.