The subtle difference between Galinstan (R) and eutectic GaInSn

Gallium-based liquid metals have been employed extensively in scientific research and industrial applications. Therefore, in this work, an experimental study was conducted to show the difference between the commercial product Galinstan (R), presumably a eutectic alloy of Ga, In, and Sn, and the eutectic alloy of Ga, In, and Sn, denoted Galinstan in literature (in this article EGaInSn). The experimental results clearly signify that the two alloys exhibit substantially different melting temperatures (ca. -19°C Galinstan (R) and 10.8°C EGaInSn) as well as surface tension (534 mN/m Galinstan (R) and ca. 605 mN/m EGaInSn), which is ascribed to small amounts of additives in the Galinstan (R). On ground of the additives, the Galinstan (R) is not a eutectic alloy but a near eutectic alloy. It can be concluded that the ambiguous literature values of melting temperature and surface tension can be faithfully assigned to the scrutinization of two dissimilar alloys. Therefore, we recommend to researchers using the eutectic GaInSn, to denote this in their research with EGaInSn instead of Galinstan in order to avoid confusion.