Damage evolution of ion irradiated defected-fluorite La2Zr2O7 epitaxial thin films Academic Article uri icon

abstract

  • 2017 Acta Materialia Inc. Pyrochlore-structure oxides, A2B2O7, may exhibit remarkable radiation tolerance due to the ease with which they can accommodate disorder by transitioning to a defected fluorite structure. The mechanism of defect formation was explored by evaluating the radiation damage behavior of high quality epitaxial La2Zr2O7 thin films with the defected fluorite structure, irradiated with 1MeV Zr+ at doses up to 10 displacements per atom (dpa). The level of film damage was evaluated as a function of dose by Rutherford backscattering spectrometry in the channeling geometry (RBS/c) and scanning transmission electron microscopy (STEM). At lower doses, the surface of the La2Zr2O7 film amorphized, and the amorphous fraction as a function of dose fit well to a stimulated amorphization model. As the dose increased, the surface amorphization slowed, and amorphization appeared at the interface. Even at a dose of 10 dpa, the core of the film remained crystalline, despite the prediction of amorphization from the model. To inform future ab initio simulations of La2Zr2O7, the bandgap of a thick La2Zr2O7 film was measured to be indirect at 4.96eV, with a direct transition at 5.60eV.

published proceedings

  • ACTA MATERIALIA

altmetric score

  • 0.25

author list (cited authors)

  • Kaspar, T. C., Gigax, J. G., Shao, L., Bowden, M. E., Varga, T., Shutthanandan, V., ... Henager, C.

citation count

  • 19

publication date

  • May 2017