Synthesis of InSn alloy superconductor below room temperature

The eutectic point for a typical gallium indium tin (GaInSn) alloy with an atomic composition of 78% Ga, 15% In, and 7% Sn is at near room temperature. This alloy exists in the liquid state at room temperature and solidifies below 260 K. We found that the major In3Sn and minor InSn4 superconducting phases are formed in this liquid alloy below 260 K and this alloy exhibits superconductivity at 6.0 K. Therefore, we can fabricate superconducting thick films without heat treatment by simply coating a substrate with the alloy and subsequently cooling it to the alloy's superconducting transition temperature.