Gallium is unique.Learn More!
The Unique Properties of Gallium
- Melting Point: 30°C (86°F)
- Boiling Point: 2,400°C (4,352°F)
- Density: 5.90gm/cm3 (0.2133lb/in3)
- Atomic Weight: 69.7g/mol
- Atomic Number: 31
- Indalloy®: 14
Emerging Applications for Liquid Metal
Gallium: The White Light LED Revolution
EZ-Pour® Gallium Trichloride
EZ-Pour® Gallium Trichloride, Part 1
EZ-Pour® Gallium Trichloride, Part 2
The 6 Alloy Families: Gallium
Indium Corporation: Melting Gallium with Body Heat
Gallium and gallium alloys are desirable because of their low melting points.
Gallium will wet to very difficult surfaces, even glass.
Gallium can be alloyed to use as a non-toxic replacement for mercury.
EZ-Pour® Gallium Trichloride
Gallium is Unique
In its pure form, gallium is an unusual element to say the least. With a melting point of approximately 30°C, gallium is a liquid at just above room temperature. When alloyed with other elements (notably indium), the resulting melting point is below room temperature. This low melting point has made the gallium alloy family a non-toxic replacement for mercury in certain applications that require a liquid metal at room temperature.
Gallium was first extracted from sphalerite by Paul Emile Lecoq de Boisbaudran in 1875. Four years before this, the properties of the element were predicted by Dmitri Mendeleev with surprising accuracy. Since it was first discovered, the unique properties of gallium have made it suitable as a solution to many new applications and a replacement for hazardous materials in existing applications.
Gallium is most commonly used in the semiconductor industry. Various gallium-based semiconductors are used in high-end integrated circuits (ICs), lasers, solar cells, and LEDs.
As in silicon technology, the substrates that contain gallium are single crystals, sliced into wafers. Unlike Group IV Silicon, however, Group III Gallium is combined with a Group V element to create a semiconducting crystal. Thus, gallium arsenide (GaAs), gallium nitride (GaN), and other compound semiconductor materials are in use today.
On top of the crystal substrate, additional layers need to be deposited to create electronics devices (such as transistors and integrated circuits) or optical devices (such as LEDs or lasers). These additional layers are deposited by chemical or physical vapor deposition methods. The most widely used technique is MOCVD which uses metal-organic (MO) precursors to deliver the individual elements of the compound semiconductor film to be grown. In the case of gallium, the MO precursor material is trimethylgallium (TMG) which, in turn, is manufactured from gallium trichloride.
Properties of Common Gallium Alloys:
(1) Geratherm Medical AG, Material Safety Data Sheet, 93/112/EC, 2004.)
(2) Michael D. Dickey, et al., Eutectic Gallium-Indium (EGaIn): A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature, Advanced Functional Materials, 2008, 18, 1097-1104.
(3) C.Y.Ho, et al., Thermal Conductivity of the Elements, Journal of Physical Chemical Reference Data, Vol. 1. No. 2, 1972.
(4) Charles Kittle, Introduction to Solid State Physics, 7th Ed., Wiley and Sons, 1996.