Mechanical properties, elastic constants, lattice vibrations of Gallium Arsenide (GaAs)
Mechanical properties, elastic constants, lattice vibrations
Basic ParameterElastic constants
Acoustic Wave Speeds
Phonon frequencies
Basic Parameter
| Bulk modulus | 7.53·1011 dyn cm-2 |
| Density | 5.317 g cm-3 |
| Hardness on the Mohs scale | between 4 and 5 |
| Surface microhardness (using Knoop's pyramid test) | 750 kg mm-2 |
| Cleavage plane | {110} |
| Piezoelectric constant | e14=-0.16 C m-2 |
Elastic constants 300 K.
C11=11.90·1011 dyn/cm2
C12=5.34·1011 dyn/cm2
C44=5.96·1011 dyn/cm2
 | Temperature
dependences of elastic constants. For 0<T<Tm=1513K (in units of 1011 dyn cm-2) C11= 12.17 - 1.44·10-3T C12= 5.46 - 0.64·10-3T C44= 6.16 - 0.70·10-3T (Burenkov et al. [1973]) |
For T = 300 K
| Bulk modulus (compressibility-1) | Bs= 7.53·1011dyn/cm2 |
| Shear modulus | C'= 3.285·1011dyn/cm2 |
| [100] Young's modulus | Yo= 8.59·1011dyn/cm2 |
| [100] Poisson ratio | σo = 0.31 |
Acoustic Wave Speeds
| Wave propagation Direction | Wave character | Expression for wave speed | Wave speed (in units of 105 cm/s) |
| [100] | VL | (C11/ρ )1/2 | 4.73 |
| VT | (C44/ρ )1/2 | 3.35 | |
| [110] | Vl | [(C11+Cl2+2C44)/2ρ ]1/2 | 5.24 |
| Vt|| | Vt||=VT=(C44/ρ)1/2 | 3.35 | |
| Vt⊥ | [(C11-C12)/2ρ]1/2 | 2.48 | |
| [111] | Vl' | [(C11+2C12+4C44)/3ρ]1/2 | 5.4 |
| Vt' | [(C11-C12+C44)/3ρ]1/2 | 2.8 |
Phonon frequencies
(in units of 1012 Hz) (Waugh and Dolling [1963])| νTO(Γ) | 8.02 | νLO (X) | 7.22 |
| νLO(Γ) | 8.55 | νTA(L) | 1.86 |
| νTA(X) | 2.36 | νLA(L) | 6.26 |
| νLA(X) | 6.80 | νTO(L) | 7.84 |
| νTO(X) | 7.56 | νLO(L) | 7.15 |