 | |
| Identifiers | |
|---|---|
3D model (JSmol) | |
| ChemSpider |
|
| ECHA InfoCard | 100.041.126 |
| EC Number |
|
| |
| |
| Properties | |
| AlAs | |
| Molar mass | 101.9031 g/mol |
| Appearance | orange crystals |
| Density | 3.72 g/cm3 |
| Melting point | 1,740 °C (3,160 °F; 2,010 K) |
| reacts | |
| Solubility | reacts inethanol |
| Band gap | 2.17 eV (indirect)[1] |
| Electron mobility | 200 cm2/(V·s) (300 K) |
| Thermal conductivity | 0.9 W/(cm·K) (300 K) |
Refractive index (nD) | 3 (infrared) |
| Structure | |
| Zinc Blende | |
| T2d-F-43m | |
a = 566.0 pm | |
| Tetrahedral | |
| Thermochemistry | |
Std molar entropy(S⦵298) | 60.3 J/mol K |
Std enthalpy of formation(ΔfH⦵298) | −116.3 kJ/mol |
| Hazards | |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | [1910.1018] TWA 0.010 mg/m3[2] |
REL (Recommended) | Ca C 0.002 mg/m3 [15-minute][2] |
IDLH (Immediate danger) | Ca [5 mg/m3 (as As)][2] |
| Related compounds | |
Related semiconductor materials | Aluminium gallium arsenide,Aluminium indium arsenide,Aluminium antimonide,Boron arsenide |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Aluminium arsenide (AlAs) is asemiconductor material with almost the samelattice constant asgallium arsenide andaluminium gallium arsenide and widerband gap than gallium arsenide. (AlAs) can form a superlattice withgallium arsenide (GaAs) which results in its semiconductor properties.[3] Because GaAs and AlAs have almost the same lattice constant, the layers have very little induced strain, which allows them to be grown almost arbitrarily thick. This allows for extremely high performance high electron mobility, HEMT transistors, and otherquantum well devices.[4][page needed]
It has the following properties:[5]
Aluminium arsenide is a III-V compoundsemiconductor material and is an advantageous material for the manufacture ofoptoelectronic devices, such aslight emitting diodes.
Aluminium arsenide can be prepared using well-known methods, such asliquid and vapor-phase epitaxy techniques or melt-growth techniques. However, aluminium arsenide crystals prepared by these methods are generally unstable and generatearsine (AsH3) when exposed to moist air.
Little work has been reported on the preparation of aluminium arsenide, mainly because of the practical difficulties involved. Preparation from the melt is difficult because of the highmelting point of the compound (about 1,700 °C) and of the extreme reactivity of aluminium at this temperature. A few workers have prepared small crystals from the melt, andpolycrystalline ingots have also been produced. The best of this material has an impurity carrier density of the order of 1019/cm3 and is p-type.[7]
Aluminium arsenide is a stable compound; however, acid, acid fumes and moisture should be avoided. Hazardous polymerization will not occur. Decomposition of aluminium arsenide produces hazardousarsine gas andarsenic fumes.
The chemical, physical and toxicological properties of aluminium arsenide have not been thoroughly investigated and recorded.
Aluminium compounds have many commercial uses and are commonly found in industry. Many of these materials are active chemically and thus exhibit dangerous toxic and reactive properties.
Aluminium compounds have many commercial uses and are commonly found in industry. Many of these materials are active chemically and thus exhibit dangerous toxic and reactive properties. The chemical, physical andtoxicological properties of aluminium arsenide have not been thoroughly investigated and recorded; however, there are some knownchronic andacute symptoms based on chemical delivery.
Inhalation of aluminium arsenide may cause acute irritation to the respiratory system. It may also cause chronic arsenic poisoning, ulceration of the nasal septum, liver damage and cancer/diseases of the blood, kidneys and nervous system. Aluminium arsenide is poisonous if ingested and may cause gastrointestinal and skin effects and acutearsenic poisoning. Chronic implications from ingestion include arsenic poisoning, gastrointestinal disturbances, liver damage, and cancer/disease of the blood, kidneys and nervous system. If applied to the skin, aluminium arsenide may cause acute irritation, but there are no chronic health effects recorded.[8][page needed]
Precautions to be taken in handling and storage: Store in a cool, dry place in tightly sealed containers. Ensure there is good ventilation. Open and handle container with care. AlAs reacts on contact with acids or moisture to give a host of volatile, highly toxic arsenic compounds such asArsine.
