کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1271529 | 1497563 | 2012 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Lattice contraction of cerium hydrides from first-principles LDA + U calculations Lattice contraction of cerium hydrides from first-principles LDA + U calculations](/preview/png/1271529.png)
Ce can be loaded with H forming complicated continuous solid solution and compounds, and causing remarkable electronic-structure changes. First-principles pseudopotential plane wave method with adding a Hubbard parameter U for considering the strong Coulomb correlation between localized 4f electron is employed to investigate the electronic and structural properties of stoichiometric and nonstoichiometric face-centered cubic (fcc) Ce hydrides (CeHx, x = 2, 2.25, 2.5, 2.75 and 3, respectively.). The most remarkable result is the decreasing trend of the calculated lattice parameters with increasing H composition, which is resulted from the associated effects of the enhanced chemical bonding owing to the participation of Ce 5d electron and, the size effects owing to the small H atomic radius and the large volume of octahedral interstice thus in favor of reducing the atomic distance for the formation of chemical bonding between Ce and octahedral H atoms.
► Abnormal lattice contraction of Ce hydrides with increasing H is reproduced.
► Strong Coulomb correlation between localized 4f electron is reasonably considered.
► Contraction of lattice parameter results from the electronic and structural effects.
Journal: International Journal of Hydrogen Energy - Volume 37, Issue 6, March 2012, Pages 5108–5113