کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1483320 1510534 2007 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Experimental study of the dynamics of Zn2Mg Laves phase
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Experimental study of the dynamics of Zn2Mg Laves phase
چکیده انگلیسی

A way to address the problem of phonons in quasicrystals (QCs) is to compare their dynamical response with that of approximant crystalline structures. Although the Zn2Mg Laves phase is not a periodic approximant of a QC phase, its structure is a periodic packing of Friauf polyhedra which are basic units involved in the construction of larger icosahedral atomic clusters found in Frank–Kasper type quasicrystals. We report on the experimental study of the lattice dynamics of the Zn2Mg hexagonal phase using inelastic neutron scattering with a particular attention devoted to the behavior of transverse acoustic (TA) modes. For TA modes propagating along the (T) direction, polarized along the c axis, there is a strong bending of the dispersion curve. Whereas the broadening rate is rather slow, going like q2, a strong coupling of the acoustic mode with an higher energy optical mode takes place. For TA modes propagating along the (Δ) direction, polarized in the hexagonal plane, the dispersion relation reaches much higher energy: the broadening rate is however steeper, going like q4, most likely due to a mixing of several excitations in the spectral response. In any case, the width of acoustic and optical excitations is found much smaller than in quasicrystals.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 353, Issues 32–40, 15 October 2007, Pages 3182–3187
نویسندگان
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