arsenide

Arsenide is a chemical term used for compounds that contain arsenic in the form of the arsenide ion As3-, and more broadly for solid materials in which arsenic occupies a contributing lattice site with a negative oxidation state. In materials science, the name arsenide is often applied to binary compounds formed between arsenic and electropositive elements, such as gallium arsenide (GaAs), aluminum arsenide (AlAs), and indium arsenide (InAs). These compounds are widely studied for their electronic and optoelectronic properties.

Many arsenides occur as binary compounds with metals and can exhibit a range of properties from semiconducting to metallic. Examples include GaAs and InAs, which are direct- and narrow-bandgap semiconductors used in high-speed electronics and infrared optoelectronics. Other arsenides, such as nickel arsenide (NiAs) and iron arsenide (FeAs), are metallic or intermetallic and appear in various crystal structures. Calcium arsenide (Ca3As2) is another example of a compound containing arsenide. In nature, arsenides occur as minerals in which arsenic combines with metals.

Synthesis of arsenides typically involves direct reaction of arsenic with a metal at elevated temperature, alloy fabrication, or chemical vapor deposition for semiconductor materials. The resulting materials often possess high melting points and can be chemically stable, but their electrical and magnetic properties vary with composition and structure.

Safety and handling issues are important, since arsenic and many arsenide compounds are toxic. Proper engineering controls and waste management are required. Applications of arsenides include semiconductors for electronics and photonics, thermoelectric materials, and, in some families, iron-based superconductors.