کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1516738 1511567 2011 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Non-Debye behaviours of heat capacities of cubic II–VI materials
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
Non-Debye behaviours of heat capacities of cubic II–VI materials
چکیده انگلیسی

On the basis of an appropriate four-oscillator version of a representative dispersion-related hybrid model we perform detailed analyses of isobaric heat capacity data available for cubic ZnS, ZnSe, ZnTe, CdTe, HgSe, and HgTe. Characteristic non-Debye behaviours of the Cp(T) data sets under study, which are manifested above all in form of non-monotonic dependences (maxima) of the respective Cp(T)/T3 curves in the cryogenic region, are described in terms of two Einstein oscillators for short-wave transversal acoustic (TA) phonons in combination with relatively weak components of Debye and non-Debye type due to long-wave acoustic phonons. This prominent non-Debye feature is represented alternatively in the form of non-monotonic dependences (minima) of conventional Debye temperature curves, ΘD(T). The close correlation between the low-temperature asymptotic (decreasing vs. increasing) sections of ΘD(T) vs. Cp(T)/T3 curves is described by simple algebraic formulae. The maxima positions of the latter are shown to be nearly proportional to the centre of gravity positions of the respective TA phonon spectra sections. The inherent non-Debye nature of the whole phonon density of states (PDOS) spectra is shown to find its global expression in characteristic snakelike shapes of the equivalent, moment-related phonon energy curves.


► We display of an elaborate analytical framework of non-Debye type.
► We perform high accuracy analyses of heat capacities for cubic III–V materials.
► Snakelike phonon energy curves indicate the non-Debye nature of phonon spectra.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Physics and Chemistry of Solids - Volume 72, Issue 11, November 2011, Pages 1296–1311
نویسندگان
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