Structural characterization and optical properties of UO2 thin films by magnetron sputtering

First-principles study of the electronic structure and optical properties of UO2

“…In our previous work, we prepared UO 2 thin films by magnetron sputtering method [28]. Refractive indices and extinction coefficients were obtained by ellipsometric spectroscopy measurements.…”

Modified Tauc–Lorentz dispersion model leading to a more accurate representation of absorption features below the bandgap

“…The optical properties of the uranium oxide films deposited by magnetron sputtering were determined over different spectral ranges by spectroscopic ellipsometry in Refs. [90,91]. The UO x dielectric functions in these references were obtained by applying the Drude-Lorentz model [90] and point-by-point data inversion [91] (the latter uses six different methods of the band gap determination based on linear extrapolation of various functional dependences for ε 2 and the absorption coefficient α).…”

Chemical Vapor Deposition of Phase‐Pure Uranium Dioxide Thin Films from Uranium(IV) Amidate Precursors

“…[1] Defect formation and void swelling in UO 2 fuel pellets dramatically reduce the lifetime and energy output of these materials,b ut the direct study of the surface oxidation processes that cause these defects can be challenging due to the chemical complexity and extreme radioactivity of spent fuels. [1][2][3] Due to their large active surface areas,phase-pure UO 2 thin films can serve as an excellent model systems for the chemical and physical changes that occur at the grain boundaries of bulk UO 2 fuel pellets.U ranium oxide thin films have been fabricated using both solution [4][5][6] and sputtering [7][8][9][10] methods;h owever,a chieving stoichiometric control in the resulting films has been challenging due to the wide array of accessible uranium oxide phases and the facile interconversion of these phases at grain boundaries. [5,11] Consequently,m any published studies on uranium oxide have been performed using materials with avarying degree of amorphous or polycrystalline character.…”