About Aluminium Phosphide (AlP)
Performance

Aluminium phosphide (aluminum phosphide) is a highly toxic inorganic compound with the chemical formula AlP used as a wide band gap semiconductor and a fumigant. This colorless solid is generally sold as a grey-green-yellow powder due to the presence of impurities arising from hydrolysis and oxidation.
Properties,
AlP crystals are dark grey to dark yellow in color and have a zincblende crystal structure with a lattice constant of 5.4510 Å at 300 K. They are thermodynamically stable up to 1,000 °C (1,830 °F).
Aluminium phosphide reacts with water or acids to release phosphine:
AlP + 3 H2O → Al(OH)3 + PH3
AlP + 3 H+ → Al3+ + PH3
Preparation
AlP is synthesized by combination of the elements:
4Al + P4 → 4AlP
Caution must be taken to avoid exposing the AlP to any sources of moisture, as this generates toxic phosphine gas.
Semiconductor applications
Industrially, AlP is a semiconductor material that is usually alloyed with other binary materials for applications in devices such as light-emitting diodes (e.g. aluminium gallium indium phosphide).
Toxicology
Main article: Aluminium phosphide poisoning
Evidently poisonous, aluminium phosphide has been used for suicide. Fumigation has also caused unintentional deaths, such as examples in Saudi Arabia and the United States.Known as "rice tablet" in Iran, for its use to preserve rice, there have been frequent incidents of accidental or intentional death. There is a campaign by the Iranian Forensic Medicine Organization to stop its use as a pesticide.
Aluminium phosphide poisoning is considered a wide-scale problem in the Indian subcontinent.
Base infomation
Name: Aluminum phosphide
Aluminium(III) phosphide,
Aluminium monophosphide
CAS Number:20859-73-8
ChemSpider:28171
EC Number:244-088-0
PubChem:30332
RTECS number:BD1400000
UNII:E23DR6L59S
Chemical formula:AlP
Molar mass:57.9552 g/moll
Appearance:Yellow or gray crystals
Odor:garlic-like
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Density:2.85 g/cm3
Melting point:2,530 °C (4,590 °F; 2,800 K)
Solubility in water:reacts
Band gap:2.5 eV (indirect)
Refractive index (nD):2.75 (IR), ~3 (Vis)
Crystal structure:Zincblende
Space group:T2d-F43m
Lattice constant:a = 546.35 pm
Coordination geometry:Tetrahedral
Thermochemistry
Std molar entropy (So298):47.3 J/mol K
Std enthalpy of formation (ΔfHo298):-164.4 kJ/mo |
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