کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9837598 | 1525280 | 2005 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Lattice vibrations in high-pressure phases of LiYF4
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Possible variations in the dynamical behaviour of LiYF4 due to its several structural changes under pressure are examined by quasi-harmonic lattice dynamics calculations. The phonon spectra in the entire Brillouin zone together with the respective Gibbs free energies are calculated for the three high-pressure polymorphs of LiYF4 (that are stable at T=0) with a view to better understand their relative stabilities as functions of pressure and temperature. The present work predicts anomalous thermal expansion at low temperatures in phases I and IIa. Molecular dynamics simulations provide qualitative impressions about a temperature-driven second-order transition and also of kinetic effects in the subsequent pressure-driven first-order phase transformation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 363, Issues 1â4, 15 June 2005, Pages 213-224
Journal: Physica B: Condensed Matter - Volume 363, Issues 1â4, 15 June 2005, Pages 213-224
نویسندگان
A. Sen, S.L. Chaplot, R. Mittal,