Liquid metal Liquid metal Liquid metal consists of alloys with very low melting points which form a eutectic that is liquid at room temperature. The standard metal used to be mercury, but gallium-based alloys, which are lower both in their vapor pressure at room temperature and toxicity, are being used as a replacement in various applications. A few elemental metals are liquid at or near room temperature. The most well known is mercury(Hg), which is molten above −38.8 °C (234.3 K, −37.9 °F). Others include caesium(Cs), which has a melting point of 28.5 °C (83.3 °F), rubidium (Rb)(39 °C [102 °F]), francium
Liquid metal ion source allowed to flow to the apex of a sharp needle. Most focused ion beam instruments use a liquid-metal ion sources (LMIS) often with gallium. In a gallium LMIS, gallium metal is placed in contact with a tungsten needle and heated gallium wets the tungsten and flows to the tip of the needle where the opposing forces of surface tension and electric field produce the cusp shaped Taylor cone. The tip radius of this cone is ~2 nm. The electric field at this small tip is typically greater than 1 x 10 V/cm and causes ionization and field emission of the