INVESTIGADORES
KOVAL Sergio Fabian
congresos y reuniones científicas
Título:
The Origin of ferroelectricity in H-bonded KDP crystals
Autor/es:
S. KOVAL; J. KOHANOFF; R. L. MIGONI
Lugar:
Madrid
Reunión:
Conferencia; X International Meeting on Ferroelectricity - IMF10; 2001
Resumen:
Abstract:Based on an accurate first principles description of the energetics in
H-bonded potassium-dihydrogen-phosphate crystals, we conduct a first
study of nuclear quantum effects and of the changes brought about by
deuteration. Tunneling is allowed only for clusters involving correlated
protons and heavy ion displacements, the main effect of deuteration
being a depletion of the proton probability density at the O-H-O bridge
center, which in turn weakens its proton-mediated covalent bonding. The
ensuing lattice expansion couples self-consistently with the proton
off-centering, thus explaining both the giant isotope effect and its
close connection with geometrical effects.