کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
5452968 1513870 2018 7 صفحه PDF سفارش دهید دانلود کنید
عنوان انگلیسی مقاله ISI
Light impurity atoms as the probes for the electronic structures of actinide dioxides
ترجمه فارسی عنوان
اتم های ناخالص نور به عنوان پروب برای ساختارهای الکترونیکی دی اکسید های اکتینید
کلمات کلیدی
دی اکسید اکتینید، ناخالصی ها، انرژی تئوری کاربردی تراکم، ساختار الکترونیکی،
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مکانیک محاسباتی
چکیده انگلیسی


- The general trends of energetics and stability of light impurities in AnO2 are firstly reported.
- The delocalization → localization transition of 5f electron is the origin of impurity effect.
- Hydrogen is very valuable in understanding the differences in the electronic structures of AnO2.

First-principles density functional theory are used to calculate the formation energies of ten light impurities X (X: H, He, Li, Be, B, C, N, O, F and Ne) in seven actinide dioxides AnO2 (An: Th, Pa, U, Np, Pu, Am and Cm), in order to elucidate the relative stability of X and to obtain some trends of impurities behaviors. The Hubbard parameter U is used to describe the strongly correlated electron behavior of An 5f electrons. The results indicate that the formation energies of X significantly depend on the properties of AnO2 and X. For X at the octahedral interstitial sites of AnO2, F is the only energetically favorable impurity for all AnO2, owing to its strong oxidability; H in PaO2, O in PaO2 and UO2, Li in PuO2, AmO2 and CmO2, Be in AmO2 and CmO2 are also energetically favorable. The oxidability or reductivity of X and the delocalization → localization transition of 5f electrons across actinide series can account for the trends of the behaviors of X in AnO2. Particularly, H, a very typical amphoteric element, is chosen to illustrate its difference existence states in AnO2. H prefers to occupy the octahedral interstitial sites of early AnO2 or form hydroxyl group in the later AnO2.

The formation energy of the amphoteric impurity H can sensitively reflect the delocalization → localization transition of 5f electrons across the AnO2 series. H tends to oxidize or reduce AnO2 with delocalized or localized 5f electrons, corresponding to form nominal [(AnO2)n]+H− and [AnnO2n−1]+[OH]−, respectively.139

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computational Materials Science - Volume 142, 1 February 2018, Pages 25-31
نویسندگان
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