Compositional dependence of longitudinal sound velocities of piezoelectric (111) InxGa1-xAs measured by picosecond ultrasonics
Journal
Journal of Applied Physics
Journal Volume
100
Journal Issue
10
Pages
103516
Date Issued
2006-11
Author(s)
Abstract
Picosecond ultrasonic experiments were performed to generate and detect acoustic pulses in piezoelectric (111) epilayers of InxGa(1−x)As, and the longitudinal sound velocities in the [111] direction of InxGa(1−x)As were thus directly determined by controlling the indium content x. We found that the sound velocity exhibits an obvious bowing with different alloy compositions and can be described as a quadratic function of VL(x)=458x2−1451x+5414. This result supports a nonlinear compositional dependence of the elastic constants of InxGa(1−x)As and indicates that the linear-interpolation approximation is inapplicable for estimating sound velocity in this specific case.
Type
journal article