Title

Anisotropy in periodic mesoporous silica and organosilica films studied by generalized ellipsometry

Document Type

Article

Publication Date

12-2005

Abstract

The dielectric functions of a series of periodic mesoporous silica as well as periodic mesoporous organosilica thin films were measured using generalized variable angle spectroscopic ellipsometry over the spectral range 300–1400nm" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px 2px 0px 0px; margin: 0px; position: relative;">300–1400nm300–1400nm. Ellipsometry results indicate that following template removal, both types of films possess uniaxial anisotropy, with the optic axis perpendicular to the plane of the film. This anisotropy is apparently caused by the structural distortion of the channels, oriented primarily parallel to the substrate plane. We also find that the birefringence increases as a function of porosity.

Journal

Applied Physics Letters

Volume

87