Aluminum nitride, referred to as azanylidynealumane in IUPAC nomenclature, is an inorganic compound of aluminum and nitrogen represented by the chemical formula AlN ^[1]. It is not a naturally-occurring compound and has to be artificially synthesized ^[2]. It is characterized by high thermal conductivity and electrical resistivity, as well as an excellent corrosion resistance ^[2].

 

Aluminum Nitride Identification
CAS Number	24304-00-5 [1, 3]
PubChem CID	90455 [1]
ChemSpider ID	81668 [4]
ChEBI	CHEBI:50884 [5]
EC Number	246-140-8 [1, 3]
RTECS Number	N/A [3]
InChI Key	PIGFYZPCRLYGLF-UHFFFAOYSA-N [1]

How is Aluminum Nitride Prepared

Its synthesis involves carbothermal reduction of aluminum oxide (Al₂O₃) using gaseous nitrogen at a temperature of 1400-1700 °C ^[6]:

1. Al₂O₃ + C → Al₂O₂ + CO
2. Al₂O₂ + 2C + N₂ → 2AlN + 2CO

Sintering aids like CaO or Y₂O₃ are used, and then the mix is hot pressed to produce the dense technical-grade material.

Properties and Characteristics of Aluminum Nitride

General Properties
Molar Mass/Molecular Weight	40.989 g/mol [1]
Physical Properties
Color and Appearance	White to pale yellow powder or sheet [3, 4]
Melting Point	2200 °C, 3990 °F [3]
Boiling Point	2517 °C, 4563 °F [3]
Density	2.9-3.3 g cm-3 [3]
State of matter at room temperature (solid/liquid/gas)	Solid [3]
Solubility	Slightly soluble in mineral acids, decompose in water solutions containing acids and bases [7]
Solubility in Water	Insoluble (monocrystalline form), hydrolyzes (powder form)
Thermal Conductivity	80-200 W/K.m [3]
Volume Resistivity	1010-1016 Ω.cm [8]
Dielectric Constant	9.14 [9]
Hardness	1100 Kg/mm2 [10]
Thermal Emissivity (100 °C)	0.93 [11]
Infrared Refractive Index (300 K)	2.1-2.2 (monocrystals and epitaxial films), 1.9-2.1 (polycrystalline films), 1.8-1.9 (amorphous films) [9]
Lattice Constant (300 K) a and c	3.11(1) Å and 4.98(1) Å [9]
Atomic Properties
Crystal Structure	Wurtzite

What is It Used for

• A thin film of crystalline aluminum nitride, because of its piezoelectric properties, is used for developing small surface acoustic wave sensors (SAWs) on silicon wafers ^[12].
• RF filters in mobile phones consist of a microelectromechanical system (MEMS) device, called thin film bar acoustic resonator (FBAR), which uses AlN ^[13].
• A piezoelectric layer of AlN is used in making micromachined ultrasound transducers (MUTs) that have applications in velocity sensing, robotics, and medical imaging ^[14].
• Aluminum nitride nanotubes are used as chemical sensors for detecting toxic gases ^[15].
• Currently, there is research into manufacturing light-emitting diodes that use gallium-aluminum nitride-based semiconductors for improved emission efficiency ^[16].

Aluminum Nitride Toxicity

Exposure to AlN through mouth, inhalation, or injection may cause bone and lung toxicity ^[17]. Repeated exposure can irritate the eyes and skin ^[17].

References
1. Aluminum Nitride (AlN) – Pubchem.ncbi.nlm.nih.gov
2. Aluminum Nitride (AlN) – Surmet.com
3. Aluminum Nitride – Americanelements.com
4. Aluminium nitride – Chemspider.com
5. CHEBI:50884 – aluminium nitride – Ebi.ac.uk
6. Carbothermal Synthesis Of Aluminum Nitride Using Sucrose – Digitool.library.mcgill.ca
7. Aluminum nitride – Chemicalbook.com
8. Effects of adding Y2O3 on the electrical resistivity of aluminum nitride ceramics – Jstage.jst.go.jp
9. AlN – Aluminum Nitride Basic Parameters – Ioffe.ru
10. Aluminum Nitride, AlN Ceramic Properties – Accuratus.com
11. Aluminum Nitride Property List – Matsuo-sangyo.co.jp
12. Aluminum Nitride on Sapphire Films for Surface Acoustic Wave Chemical Sensors – Jhuapl.edu
13. AlN and ScAlN Contour Mode Resonators for RF Filters – Osti.gov
14. Aluminum Nitride Piezoelectric Micromachined Ultrasound Transducer Arrays – Semanticscholar.org
15. Aluminum Nitride Nanotubes – Researchgate.net
16. Aluminum nitride nanowire light emitting diodes: Breaking the fundamental bottleneck of deep ultraviolet light sources – Nature.com
17. Aluminum Nitride Safety Data Sheet – Espimetals.com