Germanium

Germanium (Ge) is a chemical element and a metalloid with atomic number 32. It was discovered in 1886 by Clemens Winkler in Freiberg, Saxony, and named after Germany. It lies in group 14 of the periodic table and shares properties with both metals and nonmetals. It exists in crystalline form with a diamond-like lattice similar to silicon. It has a relatively high refractive index in the infrared and a narrow indirect band gap of about 0.66 eV, making it a useful semiconductor material. In its elemental form at room temperature it is a brittle, lustrous solid.

Occurrence and production: Germanium is a trace element in the Earth's crust, with abundance around a few parts per million. It occurs mainly in zinc ores and certain germanium-rich minerals, and is commonly recovered as a byproduct of zinc ore processing. Major producers include China, Russia, the United States, and Canada.

Isotopes and chemistry: Natural germanium consists of five stable isotopes. Several radioisotopes are produced for research and medical uses, notably 68Ge used in generators that produce 68Ga for PET imaging.

Applications: The most important current use is in electronics and optoelectronics. Germanium was pivotal in early transistor technology; today it is used in high-purity crystals for integrated circuits, infrared optics and fiber-optic systems, and radiation detectors (high-purity germanium detectors). It is also used as a dopant in silicon technology to modify electrical properties.

Safety: Germanium compounds can be hazardous if inhaled as dust; handling is subject to standard industrial hygiene practices.