Surface acoustic waves and elastic constants of InN epilayers determined by Brillouin scattering

Abstract

The surface acoustic wave velocity in InN has been experimentally determined by means of Brillouin scattering experiments on c ‐ and m ‐face epilayers. From simulations based on the Green's function formalism we determine the shear elastic constants c66 and c44 and propose a complete set of elastic constants for wurtzite InN. The analysis of the sagittal and azimuthal dependence of the surface acoustic wave velocity indicates a slightly different elastic behavior of the m ‐face sample that basically affects the c44 elastic constant. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Comparative study of the pressure dependence of optical-phonon transverse-effective charges and linewidths in wurtzite InN

“…Before we shall examine the different contributions to the reduction of e * T with pressure in wurtzite InN, which for the E 1 mode corresponds to a coefficient of −0.9 × 10 −2 e 0 /GPa (in units of the electron elementary charge). The large positive contribution from the LO-TO splitting (+3.4 × 10 −2 e 0 /GPa) is effectively overcompensated by the reduction of the unit cell volume (−1.7 × 10 −2 e 0 /GPa), as obtained from Murnaghan's equation of state28 and the elastic constants reported in Ref [29],. but mainly by the large negative contribution from the high frequency dielectric constant ∞ (−2.6 × 10 −2 e 0 /GPa).…”

Brillouin scattering determination of the surface acoustic wave velocity in InxGa1−xN: A probe into the elastic constants

“…In all cases, the elastic constants for the end member compounds were taken from previous Brillouin studies. [9][10][11] As can be seen in Table II The Rayleigh (solid lines) and Sezawa (dashed lines) acoustic wave velocities simulated using the three different sets of alloy elastic constants mentioned above are plotted in Fig. 2 for an In concentration of x ¼ 0.75.…”

Temperature dependence of Mg-H local vibrational modes in heavily doped InN:Mg

“…In all cases, the elastic constants for the end member compounds were taken from previous Brillouin studies. [9][10][11] As can be seen in Table II from the ab initio calculations when a uniform In distribution is assumed, which imply a significant sublinear dependence on composition of these elastic constants. On the other hand, if In clustering is taken into account, the greatest bowing is exhibited by the c 11 ; c 12 , and c 44 elastic constants.…”