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Anion‐Related Differences in Phonons of (GaX) N (Ga 1‐ x Al x X) N (001) Superlattices (X=As,N)
Author(s) -
Grille H.,
Bechstedt F.
Publication year - 1996
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/(sici)1097-4555(199603)27:3/4<201::aid-jrs950>3.0.co;2-m
Subject(s) - superlattice , phonon , raman spectroscopy , ion , chemistry , condensed matter physics , electric field , spectral line , composition (language) , materials science , physics , quantum mechanics , organic chemistry , linguistics , philosophy
The phonon spectra of (GaX) N (Ga 1‐x Al x X) N (001) superlattices (X=As, N) calculated within a rigid ion model are compared. The elastic forces are characterized by a three‐parameter Keating model, while the electric field is fully included using an Ewald summation. The force constants and the effective charges are assumed to be dependent on the chemical environment. The influence of composition and disorder is described within a random‐element isodisplacement (REI) model generalized to layered structures with arbitrary wavevectors and composition profiles. Attention is focused on the differences in the spectral and localization behaviour of phonons, which are explained mainly in terms of the different anion masses.