Table 4.
Description of different deposited piezoelectrical material properties.
| Properties | ZnO | GaN | AlN | GaAs |
|---|---|---|---|---|
| Density (Kg/m3) | 5610 | 6150 | 3300 | 5317 |
| Elastic modulus (GPa) | 140 | 320 | 300–350 | 86 |
| Poisson’s ratio | 0.36 | 0.183 | 0.29 | 0.31 |
| Refractive index | 2 | 2.5 | 1.96 | 3.85 |
| Piezoelectric coefficient (pC/N), d33 | 12 | 4.5 | 4.5, 6.4 | 3.4 |
| Electromechanical coupling coefficient, k2 (%) | 1.5 | 0.13 | 3.1–8 | 0.07 |
| Wave velocity (m/s) | 2720 | 4130 | 5800 | 4730 |
| Dielectric constant | 8.66 | 8.9 | 8.5–10 | 12.9 |
| Coefficient of thermal expansion (/°C) | 6.5 × 10−6 | 3.17 × 10−6 | 5.2 × 10−6 | 5.73 × 10−6 |