Indium was discovered in 1863 by Reich and Richter in the course of a spectroscopic study of blends. Intrigued by a dominant indigo blue line, they succeeded in isolating a new element, which they called indium as a reminder of the characteristic colour of its spectrum.
- A shiny metal that is very malleable and ductile.
- Like lead, it can be scratched with the nail.
- Does not tarnish in air.
- When bent, it produces a noise comparable with the tin-cry.
- Indium oxide and tin-doped indium oxides are used as transparent conducting coatings applied to glass and polymer films, e.g. in opto-electronic devices such as Liquid Crystal Displays (LCD).
- High-purity indium (6N and above) has found applications in electronics, e.g. as InP single crystals as well as in CIGS solar cells
- Indium's first important use was for the manufacture of bearings that have to withstand highly demanding working conditions, e.g. in aircraft engines.
- A component of low melting-point alloys (down to 42°C) as used for glass-to-glass or glass-to-metal joints, and of special solders for use mostly in the electronics industry.
- Used in the manufacture of sodium-vapour lamps in the form of an indium oxide deposit on the inner surface of the bulb to increase efficiency and luminosity.
- Is replacing mercury in zinc powders used in alkaline batteries (green batteries), the aim being to slow down the spontaneous discharge that occurs during storage, i.e. to increase the shelf life.
- An 80% Ag–15 In–5 Cd alloy is used in the manufacture of absorber rods in nuclear reactors.
Indium is recovered from targets that are used for conductive coatings. Recovery of indium from dissipative uses like flat panel displays and photovoltaics remains very challenging.