11. GERMANIUM

11. GERMANIUM

Germanium is a brittle silver-grey element with properties intermediate between the properties of silicon and tin. It is distributed widely in the Earth’s crust as the sulphide or associated with sulphide ores of other elements. In 1871 the great Russian scientist D. I. Mendelyeev accurately predicted many of the properties of this element from a study of the properties of adjacent elements in the Periodic Table. Germanium was finally isolated in 1886 by C. A. Winkler and named after his native country of Germany. The first commercial production of the free element began in 1942.

When alloyed with small amounts of other elements, germanium permits electric current to pass through its surface in only one direction. This property enabled germanium crystals to serve as a rectifier. Since it is a semiconductor, germanium is used in transistors for amplification of small currents of electricity. The chief use of germanium is in the manufacture of electronic semiconductor devices. It must be of very high purity.

Although expensive and rare, germanium is sometimes used to give hardness to certain alloys.