کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7987996 | 1515533 | 2018 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
First-principles study of ternary Li-Al-Te compounds under high pressure
ترجمه فارسی عنوان
مطالعه اولیهای ترکیبات ترانسمیتر لیتیم-آل-تی در فشار بالا
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
دانش مواد (عمومی)
چکیده انگلیسی
The ternary Li-Al-Te compounds were investigated by the first-principle evolutionary calculation based on density function theory. Apart from the known structure, I-42d LiAlTe2 and P3m1 LiAlTe2, several new structures were discovered, P-3m1 LiAlTe2, Pnma LiAlTe2, C2/c Li9AlTe2, Immm Li9AlTe2 and P4/mmm Li6AlTe. We determined that the I-42d LiAlTe2 firstly changed to P-3m1 phase at 6Â GPa, and then into the Pnma structure at 65Â GPa, Pnma phase was stable up at least to 120Â GPa. I-42d LiAlTe2 was a pseudo-direct band gap semiconductor, but P-3m1 LiAlT2 was an indirect band gap semiconductor. This may be caused by the pressure effect. Subsequently, it was metallized under pressure. Pnma LiAlTe2 was also metallic at the pressure we studied. C2/c Li9AlTe2 was stable above 4Â GPa, then turned into Immm phase at 60Â GPa. C2/c Li9AlTe2 was an indirect band gap semiconductor. The results show that P4/mmm Li6AlTe was stable and metallized in the pressure range of 0.7-120Â GPa. The calculations of DOS and PDOS indicate that the arrangement of electrons near Fermi energy can be affected by the increase of Li. The calculated ELF results and Bader charge analysis indicate that there was no covalent bond between Al and Te atoms for high-pressure Pnma LiAlTe2, Li9AlTe2 and Li6AlTe. For Li9AlTe2 and Li6AlTe, different from LiAlTe2, Al atoms not connect with Te atoms, but link with Li atoms. The results were further proved by Mulliken population analysis. And the weak covalent bonds between Li and Al atoms stem from the hybridization of Li s and Al p presented in PDOS diagrams. We further deduced that the pressure effect and the increase of Li content may result in the disappearance of Al-Te bonds for Li-Al-Te compound under extreme pressure.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solid State Communications - Volume 270, February 2018, Pages 58-64
Journal: Solid State Communications - Volume 270, February 2018, Pages 58-64
نویسندگان
Youchun Wang, Fubo Tian, Da Li, Defang Duan, Hui Xie, Bingbing Liu, Qiang Zhou, Tian Cui,