INVESTIGADORES
KOVAL Sergio Fabian
congresos y reuniones científicas
Título:
Electronic polarizability effects on the anharmonic phonon shift and damping in ionic crystals
Autor/es:
A. GRECO; S. KOVAL; R. MIGONI
Lugar:
Pichidangui
Reunión:
Simposio; XII Simposio Latinoamericano de Física del Estado Sólido, SLAFES; 1992
Resumen:
Abstract:The authors apply a previously developed perturbative formalism for
anharmonic shell models to the calculation of phonon shifts and widths
in a one-dimensional model of a solid with polarizable ions. They
analyse these properties for different k-points in the Brillouin zone
and also as a function of temperature for fixed k. They compare the
results for several values of the core-shell coupling constant g with
those obtained by using a rigid-ion model (g to infinity ). They show
that the electronic polarizability of ions leads to significant
modifications of the k-dependences as well as of the ratio between the
damping and shift. They give an interpretaton of existing discrepancies
between theory and experiment for anharmonic phonons in silicon.
Finally, they mention some further applications.