Damage evolution of ion irradiated defected-fluorite La 2 Zr 2 O 7 epitaxial thin films
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. In this paper, 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 1 MeV 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 4.96 eV, with a direct transition at 5.60 eV.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1342222
- Alternate ID(s):
- OSTI ID: 1550599
- Report Number(s):
- PNNL-SA-121946; PII: S1359645417300228; TRN: US1700529
- Journal Information:
- Acta Materialia, Vol. 130, Issue C; ISSN 1359-6454
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Composition‐dependent intrinsic defect structures in pyroclore RE 2 B 2 O 7 ( RE = La, Nd, Gd; B = Sn, Hf, Zr)
|
journal | August 2019 |
Modulating the thermal conductivity of La 2 Zr 2 O 7 by Thorium (Th) doping: an ab initio study
|
journal | September 2019 |
Theoretical investigations of electronic and thermodynamic properties of Ce doped La 2 Zr 2 O 7 pyrochlore
|
journal | May 2019 |
Similar Records
Bubble formation and lattice parameter changes resulting from He irradiation of defect-fluorite Gd2Zr2O7
{delta}-Phase to defect fluorite (order-disorder) transition in the R{sub 2}O{sub 3}-MO{sub 2} (R = Sc, Tm, Lu; M = Zr, Hf) systems