Optical anisotropy of highly oriented pyrolytic graphite. Effect of surface preparation

Abstract

Abstract Polarized reflectivity spectra are obtained at near normal incidence from highly oriented pyrolytic graphite surfaces which contain the c ‐axis (i.e. normal to the cleavage surface). Comparison of spectra from polished and sputter‐etched surfaces leads to conclude ϵ ∥ ≦ 3.4, consistent with previous determinations by oblique incidence reflectivity and by ellipsometry but substantially lower than recent values based on normal incidence spectra from polished surfaces. The nature of the polish‐induced damage is studied by RHEED, and explains the difference between our data and previous results.