CIOP   05384
CENTRO DE INVESTIGACIONES OPTICAS
Unidad Ejecutora - UE
artículos
Título:
Optical Analysis of the Fine Crystalline Structure of Artificial Opal Films
Autor/es:
G LOZANO; L A DORADO; D. SCHINCA; R A DEPINE; H MíGUEZ
Revista:
LANGMUIR
Editorial:
AMER CHEMICAL SOC
Referencias:
Año: 2009 vol. 25 p. 12860 - 12864
ISSN:
0743-7463
Resumen:
Herein, we present a detailed analysis of the structure of artificial opal films. We demonstrate that, rather than the
generally assumed face centered cubic lattice of spheres, opal films are better approximated by rhombohedral assemblies
of distorted colloids. Detailed analysis of the optical response in a very wide spectral range (0.4 e a/ë e 2, where a is the
conventional lattice constant), as well as at perpendicular and off-normal directions, unambiguously shows that the
interparticle distance coincides very approximately with the expected diameter only along directions contained in the
same close-packed plane but differs significantly in directions oblique to the [111] one. A full description of the real and
reciprocal lattices of actual opal films is provided, as well as of the photonic band structure of the proposed arrangement.
The implications of this distortion in the optical response of the lattice are discussed.e a/ë e 2, where a is the
conventional lattice constant), as well as at perpendicular and off-normal directions, unambiguously shows that the
interparticle distance coincides very approximately with the expected diameter only along directions contained in the
same close-packed plane but differs significantly in directions oblique to the [111] one. A full description of the real and
reciprocal lattices of actual opal films is provided, as well as of the photonic band structure of the proposed arrangement.
The implications of this distortion in the optical response of the lattice are discussed.