Acoustoelastic anomaly in stressed heterostructures
نویسندگان
چکیده
We investigated the influence of stress on the acoustic wave propagation in single crystalline heterostructures using a transfer matrix method. Both Rayleigh-type and Sezawa modes exhibit an acoustoelastic anomaly, where the stress-induced change of the phase velocity is maximum for finite film thicknesses, considerably smaller than the acoustic wavelength. For Ge/Si~001! compressed by 1 GPa the velocity shift of Sezawa modes reaches exceptionally high values of about 2%. These results demonstrate the importance of stress effects on the determination of elastic constants of thin film heterostructures.
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تاریخ انتشار 2001