What is Gallium?
Gallium is a post-transition metal, these are the metallic elements located between the transition metals and the metalloids (non-metals) on the periodic table. Post-transition metals have some of the properties of the transition metals but are often softer and less conductive. The post-transition metals include some of the Boron family elements such as Aluminium, Indium and Thallium, as well as Tin, Lead and Bismuth.
What are Gallium´s properties?
Gallium has some unique qualities. For example, although it is a solid at room temperature (about 22 C), it is still so soft that you could cut it with a knife. In addition, it has a low melting point of 29.76 C.
Gallium bonds easily with most metals and is commonly used to make low-melting alloys. It is one of four metals (including Mercury, Rubidium and Caesium) that are liquid at or near room temperature. This means that if you were to pick up a lump of Gallium, the warmth of your hand would melt it. Once you set it down again, it will go back to its solid form.
Of these four low-melting metals, Gallium is the least reactive and least toxic, making it the safest and most environmentally friendly choice for high-temperature thermometers, barometers, heat transfer systems and cooling and heating devices.
Liquid Gallium can be quite difficult to work with, however, as it clings to glass, skin and most other materials (except graphite, quartz and Teflon). It also expands when it freezes, so it cannot be stored in glass containers.
On the other hand, Gallium’s boiling point is quite high at 2,204 C, resulting in one of the greatest ratios between melting point and boiling point of any element. At low temperatures, Gallium is a brittle solid that breaks quite easily and, similar to glass, it shatters.
Uses for Gallium
Gallium is mainly used in electronics. Most of the Gallium produced is used to make Gallium arsenide, a compound used in microwave and infrared circuits, semiconductors and blue and violet LEDs. Gallium arsenide can produce laser light directly from electricity and is used in solar panels, including those on the Mars Exploration Rovers. On the other hand, the compound Gallium nitride (GaN) is used as a semiconductor in Blu-ray technology, mobile phones and pressure sensors for touch switches. Gallium arsenide solar cells are also much more efficient than those made of conventional Silicon and are being used in solar-powered cars and in space probes.
Art and Design
The application of Gallium is rarely seen in our day-to-day life. However, jewellery designer Sara Chyan takes advantage of its low melting point, which allows her to instill a heat factor into her jewellery pieces. This transition between solid and liquid phases caused by temperature gives the metal an emotional characteristic and transforms the metallic into an emotional symbol.