ISSN:
0142-2421
Keywords:
Brillouin light scattering
;
Si/Ge superlattices
;
elastic constants
;
surface acoustic waves
;
supermodulus effect
;
surface sound velocity
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
The elastic properties of Si/Ge strained-layer superlattices have been studied by means of Brillouin light scattering spectroscopy in order to verify the validity of the most reliable explanations for the so-called ‘supermodulus effect’. The superstructures, grown along the [001] direction, have composition modulation wavelengths ranging from 1.4 to 5.6 nm and Si/Ge ratios 1/1, 3/1, 4/1 and 1/4. The study has been carried out in three different stages: a check of the non-influence of the substrate on the determination of the elastic properties; the angular dependence of the surface sound velocity within the surface plane; the variation of the phase velocity with the modulation wavelength. No evidence of the anomalous supermodulus effect has been found in these superlattices, which can be explained on the basis of the latest theoretical predictions. In addition, the obtained data of hypersonic surface waves are in good agreement with previous results reported in Si and Ge pure single crystals. © 1997 John Wiley & Sons, Ltd.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
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