TY - JOUR
T1 - Ion irradiation induced changes in defects of iron thin films
T2 - Electron microscopy and positron annihilation spectroscopy
AU - Xu, Ke
AU - Weber, Marc H.
AU - Cao, Yue
AU - Jiang, Weilin
AU - Edwards, Dan J.
AU - Johnson, Bradley R.
AU - McCloy, John S.
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Single crystal Fe thin films (∼250 nm) were grown on MgO substrates and irradiated with 2.0 MeV Fe+ ions at 10 and 50 dpa, and the defect evolution was studied using high resolution Transmission Electron Microscopy (HR-TEM) and Doppler Broadening Positron Annihilation Spectroscopy (PAS). It was shown that irradiation induced or exacerbated a thin oxide layer at the outer interface and produced substantial Fe/Mg mixing at the film/substrate interface, particularly for the higher dose. Modeling of the PAS data allowed interpretation of the defect types at different distances from the Fe surface, and included several types of MgO substrate damage and annihilation condition changes, indicative of damage due to ballistic effects of the Fe atoms as well as chemical changes due to implantation and subsequent diffusion. This detailed PAS study compared with TEM and energy dispersive spectroscopy (EDS) provides significant insight into depth-dependent defect creation. These results will be useful for predicting defect creation in Fe-based materials under irradiation conditions, for extension to neutron irradiated structural materials.
AB - Single crystal Fe thin films (∼250 nm) were grown on MgO substrates and irradiated with 2.0 MeV Fe+ ions at 10 and 50 dpa, and the defect evolution was studied using high resolution Transmission Electron Microscopy (HR-TEM) and Doppler Broadening Positron Annihilation Spectroscopy (PAS). It was shown that irradiation induced or exacerbated a thin oxide layer at the outer interface and produced substantial Fe/Mg mixing at the film/substrate interface, particularly for the higher dose. Modeling of the PAS data allowed interpretation of the defect types at different distances from the Fe surface, and included several types of MgO substrate damage and annihilation condition changes, indicative of damage due to ballistic effects of the Fe atoms as well as chemical changes due to implantation and subsequent diffusion. This detailed PAS study compared with TEM and energy dispersive spectroscopy (EDS) provides significant insight into depth-dependent defect creation. These results will be useful for predicting defect creation in Fe-based materials under irradiation conditions, for extension to neutron irradiated structural materials.
UR - http://www.scopus.com/inward/record.url?scp=85071867477&partnerID=8YFLogxK
U2 - 10.1016/j.jnucmat.2019.151774
DO - 10.1016/j.jnucmat.2019.151774
M3 - Article
AN - SCOPUS:85071867477
SN - 0022-3115
VL - 526
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
M1 - 151774
ER -