Full text loading...
Brillouin spectra of sample A1182 (x = 0.75) obtained at different sagittal angles. Solid lines are Lorentzian line shape fits to the spectra. The Rayleigh and Sezawa peaks are labeled as R and Sw, respectively.
Surface acoustic wave velocities as a function of kh for an In x Ga1− x N layer with x = 0.75, as obtained from the Green’s function simulations using different interpolation schemes for the elastic constants: Vegard-like linear interpolation (green lines), ab initio results for a uniform alloy (blue lines), idem for a clustered alloy (red lines). The circles represent the experimental Brillouin data. R and Sw stand for Rayleigh and Sezawa modes, respectively.
Composition dependence of the surface acoustic velocity of In x Ga1− x N. Circles are the experimental values measured in this work. The triangle represents the measured value for InN reported in Ref. 11 . The solid line is the simulated considering the set of elastic constants of case iii (see text), which take into account the effect of In clustering in the alloy.
Characteristics of the In x Ga1− x N samples and their respective SAW velocity determined from the Brillouin measurements. The SAW velocity values were determined by averaging the measurements with , for which the influence of the substrate is negligible. Here, h is the thickness of the In x Ga1− x N layer and k is the acoustic scattering wave vector (see text).
Elastic constants for the end-member compounds (in GPa) and bowing parameters used in the In x Ga1− x N SAW simulations. Note that in hexagonal symmetry crystals .
Article metrics loading...