Presenter: Devin Lewis, College of Physical and Mathematical Sciences, Physics and Astronomy
Authors: Devin M Lewis, David D Allred, R. Steven Turley
Faculty Advisors: David Allred, College of Physical and Mathematical Sciences, Physics and Astronomy
Institution: Brigham Young University
We report optical constants of aluminum fluoride (AlF3) thin films deposited via thermal evaporation in the range of 5 to 50 nm. Angle-dependent reflection measurements were made using synchrotron radiation at the Advanced Light Source in Lawrence Berkeley National Labs. The experimental reflectance data were fit to obtain values for the complex index of refraction. We compare our computed constants with those computed using the independent atom approximation from the CXRO website. Their approximations only go out to 43 nm, other literature sources have measurements starting at 60 nm so an interpolation for our fitting purposes was made to that data. As expected, the real part of our fit index of refraction between 30 and 50 nm was dramatically different than simple predictions based on the independent atom approximation (IAA) While the IAA predicted that the real part of the index of refraction was less than 1 and decreased with wavelength, we saw a real part of the index of refraction which was greater than 1 and increased with wavelength. We found that the optical constants are sensitive to the manner in which the AlF3 was prepared.