Aluminum nitride is an inorganic compound with the formula AlN. It is a dark gray, metallic, and refractory material that is used in the manufacture of electronic, light, and field-emission devices. Aluminum nitride has excellent corrosion resistance to alkalies and many organic acids, and it is resistant to strong oxidizing agents. It is also a very hard and durable material that is able to withstand high temperatures.
The aluminum nitride crystal structure is a hexagonal close-packed (HCP) material that is composed of interpenetrating metal and nitrogen lattices. Each atom of the aluminum or nitrogen is bonded to four atoms of the other in a tetrahedron geometry and has a space group P63mc. The material can be made by carbothermal reduction of aluminum oxide in the presence of gaseous nitrogen or ammonia. Alternatively, direct nitridation of aluminum can be carried out in an electric arc furnace.
It is a ceramic insulator with a thermal conductivity of 270-300 W m
Aluminum nitride is used in the fabrication of microwave filters for mobile phones, as substrates for microcircuits and wafer carriers in electronic devices that require high-temperature stability, and in the production of piezoelectric micromachined ultrasound transducers. The material is also being investigated for use as a semiconductor with a gallium nitride or indium nitride heterostructures to make LEDs that can operate in the ultraviolet region at wavelengths shorter than 250 nanometers.