Elastic constants of In_xGa_1-xAs and In_xGa_1-xP determined using surface acoustic waves

Abstract

The elastic constant tensors of thin layers of InxGa1-xAs and InxGa1-xP with compositions around x = 0.5 have been determined using surface acoustic waves measured by Brillouin light scattering spectroscopy. Contrary to the case for the usual estimates, the experimentally obtained elastic constants are different from the ones calculated by simple linear combination of those of the corresponding constituent binary compounds. An averaging model combining a parallel-serial disposition of springs with the elastic constants corresponding to the binary compounds has been used to explain the elastic constants of the ternary alloys. This model explains perfectly the elastic properties of the InxGa1-xAs system, while those of the InxGa1-xP system are not reproduced.

Elastic properties of boron carbide films via surface acoustic waves measured by Brillouin light scattering

“…Calculations deliver three-dimensional graphs whose usual representation is a contour plot. In these plots, colour intensity reproduces the peaks profile corresponding to either Rayleigh or Sezawa modes [21].…”

Phononic and magnonic dispersions of surface waves on a permalloy/BARC nanostructured array

“…In contrast, the higher two SAWs leak energy into the Si substrate as their dispersion curves extend beyond the transverse bulk wave threshold [16,22-24]. The dispersion relations of the RW and Sezawa wave (SW), modeled by treating the Py/BARC array as a homogeneous effective medium [25] on a Si substrate, are presented in Figure  2a. It can be seen that the gap opening arises from the zone folding of the RW dispersions and avoided crossings at the BZ boundary.…”

Compositional dependence of the elastic constants of dilute GaAs1−xNx alloys

“…27 Since it is well known that the elastic constants obtained by Brillouin spectroscopy are slightly lower than those obtained by ultrasound techniques, 28 we carried out an additional simulation ͑D͒ with c 11 = 114 GPa, c 12 = 52 GPa, and c 44 = 57 GPa as obtained specifically by HRBS from a previous investigation of GaAs elastic constants. 29 The physical data available for the zinc blende ͑cubic͒ phase of GaN rely mostly on theoretical calculations. 30 31 however, these authors later recognized that a more accurate value ͑142 GPa͒ can be obtained by the same method using an improved basis set.…”