Cr incorporated phase transformation in Y₂O₃ under ion irradiation

Journal Article · Mon Jan 16 00:00:00 EST 2017 · Scientific Reports

DOI:https://doi.org/10.1038/srep40148· OSTI ID:1352423

Li, Nan  ^[1]; Yadav, Satyesh Kumar ^[1]; Xu, Yun ^[2]; Aguiar, Jeffery ^[3]; Baldwin, Jon Kevin Scott  ^[1]; Wang, Yongqiang  ^[1]; Luo, Hongmei ^[2]; Misra, Amit ^[4]; Uberuaga, Blas P.  ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. New Mexico State Univ., Las Cruces, NM (United States). Dept. of Chemical and Materials Engineering
3. Idaho National Lab. (INL), Idaho Falls, ID (United States)
4. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

Under irradiation, chemical species can redistribute in ways not expected from equilibrium behavior. In oxide-dispersed ferritic alloys, the phenomenon of irradiation-induced Cr redistribution at the metal/oxide interfaces has drawn recent attention. Here, the thermal and irradiation stability of the FeCr/Y₂O₃ interface has been systematically studied. Trilayer thin films of 90 nm Fe - 20 at.% Cr (1^st layer)/100 nm Y₂O₃ (2^nd layer)/135 nm Fe - 20 at.% Cr (3^rd layer) were deposited on MgO substrates at 500 °C. After irradiation, Cr diffuses towards and enriches the FeCr/Y₂O₃ interface. Further, correlated with Cr redistributed into the oxide, an amorphous layer is generated at the interface. In the Y₂O₃ layer, the original cubic phase is observed to transform to the monoclinic phase after irradiation. Meanwhile, nanosized voids, with relatively larger size at interfaces, are also observed in the oxide layer. First-principles calculations reveal that Cr substitution of Y interstitials in Y₂O₃ containing excess Y interstitials is favored and the irradiation-induced monoclinic phase enhances this process. Lastly, our findings provide new insights that may aid in the development of irradiation resistant oxide-dispersed ferritic alloys.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1352423
• Report Number(s): LA-UR-16-28998
• Journal Information: Scientific Reports, Vol. 7; ISSN 2045-2322
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY