کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7961402 | 1513930 | 2013 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Research of electronic structures and optical properties of Na- and Mg-doped β-Si3N4 based on the first-principles calculations
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
سایر رشته های مهندسی
مکانیک محاسباتی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Research of electronic structures and optical properties of Na- and Mg-doped β-Si3N4 based on the first-principles calculations Research of electronic structures and optical properties of Na- and Mg-doped β-Si3N4 based on the first-principles calculations](/preview/png/7961402.png)
چکیده انگلیسی
The atom population, electronic structures, and optical properties of Na- and Mg-doped β-Si3N4 are investigated by first-principles calculations with the generalized gradient approximation (GGA). Calculated binding and formation energies are â203.4665, â206.4901 eV and 12.8144, 9.7907 eV, respectively, suggesting that the stability increases gradually. The dropped bond population illustrates a decline in bond strength of covalent bond occurs. As obtained electron density difference pictures show that the electron missing near the Si atom between Si and N atoms turns into electron enrichment in terms of Mg intervention compared to undoped field, weakening the strength of the covalent bond. The static dielectric constant obtained at the zero frequency of the real part increases notably to 20.23 after Na doping, and markedly comes to 32.85 for Mg doping, implying its potential applications in electrics and optics. The absorption band ranges of doped systems become narrower. Both of reflectivity spectra profiles are similar and all locate at 12.5 and 15 eV, exhibiting the characteristics of some isotropy. In theoretical electron energy loss spectra, the host peaks of doped systems all locate at about 15 eV, signifying that a red-shift phenomenon occurs after doping.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computational Materials Science - Volume 79, November 2013, Pages 174-181
Journal: Computational Materials Science - Volume 79, November 2013, Pages 174-181
نویسندگان
Xuefeng Lu, Peiqing La, Xin Guo, Yupeng Wei, Xueli Nan, Ling He,