Argyrodite, heavy, dark sulfosalt mineral, a silver and germanium sulfide (Ag8GeS6), in which the element germanium was discovered (1886).
Catenation is also exhibited to a high degree by elemental silicon, germanium, and tin, but it is strictly limited in compounds of these elements; silicon may have up to 14 atoms in a chain; germanium, 9; and tin, 2 or 3 only, largely in hydrides (compounds containing hydrogen).
In the solid state, elemental carbon, silicon, germanium, and gray tin (defined as alpha tin) exist as cubic crystals, based upon a three-dimensional arrangement of bonds.
Figure 6 shows a comparison of the experimentally determined RDFs of the crystalline and amorphous forms of germanium, an elemental semiconductor similar to silicon.
The most commonly used elemental semiconductors are silicon and germanium, which form crystalline lattices in which each atom shares one electron with each of its four nearest neighbours.
Besides the elemental semiconductors, such as silicon and germanium, some binary crystals are covalently bonded.
Monocrystalline germanium, a group IV elemental semiconductor, has been widely used in the fields of solar cell, infrared optics, and so on.
Such elements include boron, silicon, germanium, antimony, selenium and tellurium.
