Properties and Overview of Gallium

Overview:

Gallium (Ga) is a soft, silvery metal primarily used in the electronics industry. It is a rare element, ranking as the 34th most abundant element in the Earth's crust, with an atomic number of 31 and the chemical symbol Ga. Gallium does not exist in its free state in nature but is extracted primarily as a by-product of aluminum and zinc production, particularly from bauxite and sphalerite ores. The extraction process involves refining the ores to separate gallium, typically in small quantities. Gallium, a soft, silvery metal, stands out among its peers due to its unique physical properties. With a melting point just above room temperature, it can literally melt in your hand, making it a fascinating element for educational demonstrations. Its unusually high boiling point gives it a wide liquid range. In its solid state, gallium is relatively soft and can be cut with a knife. It has a density of about 5.91g/cm³ at room temperature and exhibits a metallic luster when freshly cut, although it can tarnish upon prolonged exposure to air due to the formation of a thin oxide layer.
From a safety perspective, gallium is considered to be relatively safe for handling, as it is not highly toxic. However, it's crucial to take precautions. Gallium can cause skin irritation and should not be ingested. While gallium itself is not volatile, inhalation of its compounds, particularly dust or fumes from gallium arsenide, can be hazardous. Prolonged exposure to gallium compounds has been linked to respiratory and skin conditions, so it's important to use appropriate protective measures, such as gloves and masks, when handling gallium or its compounds.

Production:

Gallium is produced by extracting it from bauxite and zinc ores, with significant production occurring in countries like China, Germany, Kazakhstan, and Ukraine. Once extracted, gallium can be further refined to high-purity levels necessary for use in the electronics industry. Obtaining gallium from its ores involves several refining stages, including Bayer process-derived alumina refining and electrolysis.

Applications:

Gallium's significance in the electronics industry cannot be overstated. Its semiconducting properties are highly valued, making it a key component in high-speed electronics and optoelectronic devices, including light-emitting diodes (LEDs), laser diodes, and solar cells. The most significant application of gallium is in the production of gallium arsenide (GaAs) and gallium nitride (GaN). It's also used in the manufacture of low-melting-point alloys and has found applications in medical thermometers as a non-toxic alternative to mercury.

Summary:

Gallium is a versatile metal with unique physical and chemical properties that make it valuable in the high-tech and electronics industries. Its low melting point and its semiconducting capabilities when alloyed with elements like arsenic and nitrogen have made it indispensable in modern technology. Although gallium is generally safe, precautions are necessary to avoid potential health risks associated with prolonged exposure to its compounds.

See a comprehensive list of atomic, electrical, mechanical, physical and thermal properties for gallium below: