Elastic, anelastic, and piezoelectric coefficients of GaN

Abstract

We report elastic, anelastic, and piezoelectric coefficients of wurtzite GaN measured by resonant-ultrasound spectroscopy coupled with laser-Doppler interferometry. Five rectangular parallelepiped specimens, measuring 6.5 × 2.0 × 4.0 mm3, cut from two single crystals were used. Our values of elastic and piezoelectric coefficients were C11 = 359.4 GPa, C12 = 129.2 GPa, C13 = 92.0 GPa, C33 = 389.9 GPa, C44 = 98.0 GPa, e15 = 0.10 C/m2, e31 = 0.17 C/m2, and e33 = 0.29 C/m2. In anelastic coefficients, anisotropy was observed between Q11−1 and Q33−1.