Polarized optical reflection study on single crystalline β-FeSi2

Abstract

Polarized optical reflectance of single crystalline β-FeSi2 has been investigated up to 3.1 eV for the light polarization of E//a, E//b and E//c. We observed the clear anisotropy in the spectrums of reflectance, refractive index n, extinction coefficient k and dielectric function e, depending on the light polarizations. From the comparison with the experiments and the theoretical calculation, we found that features of those experimental spectrums agrees well with the theoretical ones calculated by the full potential linear augmented plane wave method based on the density functional theory and the dipole approximation. The anisotropy of n was found to be 10–20% between 1 eV and 3.1 eV, while it was small (<∼ 5%) below 1 eV.