Spectroscopic Ellipsometry Studies of Ferroelectric SbSe_xS_1—xI Crystals

Abstract

In the present paper the optical spectra were measured by spectroscopic ellipsometry method in the range of 0.5–5.0 eV making use of a computer-controlled photometric ellipsometer with a rotating analyzer. The measurement data were traded in terms of a pseudodielectric function (PDF) in framework of the two-phase isotropic ambient-anisotropic homogeneous sample approximation. Anisotropic properties of the sample were revealed by performing the measurement with the sample at two orthogonal orientations with respect to the plane incidence. Two components of the dielectric tensor for crystal of orthorhombic symmetry were determined. The experimental spectra of the dielectric tensor components were approximated by the contributions of Laurence oscillators in order to determine the main optical transitions to the optical response.

Keywords:

• Spectroscopic ellipsometry
• dielectric constants
• SbSeI
• SbSI

PACS:

• 71.20.Nr
• 77.22.Ch
• 78.20.Ci