Pseudodielectric Functions of Uniaxial Materials in Certain Symmetry Directions
- ORNL
The pseudodielectric function is often used to represent ellipsometric data and corresponds to the actual dielectric functions of materials when there is no surface overlayer and the material is isotropic. If a uniaxial material is oriented such that the optic axis is in the plane of incidence or is perpendicular to the plane of incidence, then the cross-polarization terms are zero and appropriate pseudodielectric functions can be determined from the ellipsometry data. We calculate the pseudodielectric functions for uniaxial crystals in three primary symmetry directions: (1) the optic axis is perpendicular to the plane of incidence, (2) the optic axis is in the plane of the sample surface and parallel to the plane of incidence, and (3) the optic axis is in the plane of the sample surface and perpendicular to the plane of incidence. These results are expanded in terms of the difference in the ordinary and extraordinary dielectric functions and compared with the approximation ofAspnes [J. Opt. Soc. Am.70, 1275 (1980)]. Comparisons are made with experimental results on oriented crystals of rutile (TiO2), and a simple procedure is presented to determine the complex dielectric function from standard ellipsometry techniques.
- Research Organization:
- Oak Ridge National Laboratory (ORNL)
- Sponsoring Organization:
- NE USDOE - Office of Nuclear Energy; SC USDOE - Office of Science (SC)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1003029
- Journal Information:
- Journal of the Optical Society of America A, Journal Name: Journal of the Optical Society of America A Journal Issue: 2 Vol. 23; ISSN 1084-7529; ISSN 1520-8532
- Country of Publication:
- United States
- Language:
- English
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