pnictides

Pnictides are chemical compounds that contain one or more pnictogen elements, the group 15 elements nitrogen, phosphorus, arsenic, antimony, and bismuth. The term, derived from pnictogen, is used for a broad class of materials in which a pnictogen forms bonds with metals, metalloids, or nonmetals. In practice, pnictides encompass a wide range of compounds, with nitrogen-, phosphorus-, arsenic-, and antimony-containing examples being the most studied.

Common classes of pnictides include nitrides (N3−), phosphides (P3−), arsenides (As3−), antimonides (Sb3−), and bismuthides (Bi3−). These compounds can exhibit ionic, covalent, or metallic bonding and cover a broad spectrum of properties. Transition-metal nitrides such as TiN and VN are known as hard, refractory ceramics, while pnictide semiconductors like gallium arsenide (GaAs) and gallium nitride (GaN) are central to modern electronics and optoelectronics.

In condensed matter physics and materials science, iron pnictides (FeAs-based compounds) form a family of high-temperature superconductors discovered in 2008. They typically feature layered crystal structures and display unconventional superconductivity when doped or subjected to pressure, making them a focal point of ongoing research.

Synthesis and crystal chemistry of pnictides vary by class, but they are generally prepared by reactions between pnictogen elements and metals or through solid-state routes. Pnictides remain active areas of study for applications in superconductivity, thermoelectrics, photovoltaics, and advanced ceramics.