Zusammenfassung
Lattice dynamics calculations in zinc blende group III nitrides
superlattices were carried out assuming the existence of interface
regions with variable thickness. The acoustic frequencies were observed
to remain practically unchanged for all values of interface thickness
from one to three monolayers. The dispersion relation, Raman spectrum
and the atomic displacements of optical modes were found to be greatly
affected by interfacing. Several Raman peaks shift toward the center
position of the spectrum with increasing interface thickness. As a
consequence, some of the Raman frequencies become quasi-coincident
giving rise to highly prominent structures in the middle range spectrum.
Effects of localization of atomic displacements at the interface regions
are shown. (C) 2003 Elsevier Science Ltd. All rights reserved.
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