Skip to content

Drawing No. EH–MT–012 // Engineering Materials

Gallium Arsenide Properties

Reviewed August 2026

Gallium arsenide is a III-V semiconductor used in high-frequency, optoelectronic and high-efficiency photovoltaic applications. Its elastic and thermal properties are anisotropic/crystal-specific.

Single-crystal GaAs · [100] elastic reference · ~300 KIII-V semiconductor crystalReference data — verify design allowables

Representative properties

The stated basis, temperature and direction are part of the value. Switch units without changing the physical reference.

Density
5,317 kg/m³
Reference value / stated test basis
Young’s modulus
85.9 GPa
Reference value / stated test basis
Poisson ratio
0.31
Reference value / stated test basis
Yield strength
N/A · brittle crystal
Reference value / stated test basis
Tensile / comparison strength
Fracture strength is surface / defect dependent
Reference value / stated test basis
Thermal conductivity
55 W/(m·K)
Reference value / stated test basis
Specific heat
330 J/(kg·K)
Reference value / stated test basis
Thermal expansion
5.73 µm/(m·K)
Reference value / stated test basis
Melting / transition temperature
1,240 °C
Reference value / stated test basis
Why this basis matters: The [100] elastic properties provide a clear comparison basis. Mechanical failure is brittle, so a generic metal-like yield or UTS would be misleading.

What changes these properties?

Engineering variability

  • Thermal conductivity depends on purity, defects, doping and temperature.
  • Single-crystal elastic constants vary with orientation.
  • Wafer fracture is controlled by surface damage, edges and processing defects.
  • At high temperature arsenic volatility and compound phase equilibrium matter in addition to nominal melting behavior.

Selection note

Used for RF electronics, lasers/LEDs, solar cells and optoelectronics where high electron mobility/direct bandgap outweigh brittleness and material cost.

Where a property is shown as qualitative rather than numeric, that is intentional: the selected source or the material physics does not justify a single comparable scalar.

How to interpret this material

Stiffness

Young’s modulus describes elastic stiffness. For crystals and composites, orientation can make one scalar modulus only a directional reference.

Strength / failure

Ductile metals can use yield and tensile strength. Brittle ceramics/semiconductors and anisotropic composites require fracture, flexural or directional strength descriptions instead.

Thermal response

Conductivity, heat capacity and expansion are temperature dependent. The last column is a melting or transition descriptor only where that physical concept is appropriate.

Technical sources

The database favors manufacturer, industry, government or academic technical references and labels secondary condition-specific datasets when a primary source does not expose a complete property set.

Related materials

← Back to full material database