ELECTRONIC TRANSITIONS AND DIELECTRIC PROPERTIES OF URANIA AND THORIA

Abstract

The band-to-band transition energies for uranium oxide and thorium oxide single-crystal actinide samples were found and compared using spectral ellipsometry and critical-point dielectric function tests. Using spectroscopic ellipsometry, a wide range of wavelengths from deep ultraviolet to near-infrared were examined to determine the dielectric properties of thorium oxide and uranium oxide. Despite their similarities, ThO2's critical point structure is far more blue light biased than UO2's. The bandgap energy of ThO2 is 5.4 eV, while that of UO2 is 2.1 eV.