Topic
Debye model
About: Debye model is a research topic. Over the lifetime, 7462 publications have been published within this topic receiving 133987 citations.
Papers published on a yearly basis
Papers
More filters
01 Jan 1981
TL;DR: In this paper, the experimental situation of amorphous solids is reviewed and it is not altogether clear what fraction, if any, of the specific heat anomaly is truly intrinsic, independent of the prior history of the sample and of the presence of trace impurities.
Abstract: One of the puzzles presented by amorphous solids is that their low-temperature specific heat exceeds that predicted on the basis of the Debye theory by a considerable amount. This phenomenon appears to be sufficiently general to be considered a characteristic one. However, it is not altogether clear what fraction, if any, of the specific heat anomaly is truly intrinsic, i.e., independent of the prior history of the sample and of the presence of trace impurities. In this chapter we will review the experimental situation.
42 citations
TL;DR: In this paper, the thermal expansion of rare earth zirconate pyrochlore was studied by the Debye and quasi harmonic approximation combined with the first principles calculations, and the difference between CV and CP was obtained.
Abstract: The thermal expansions of the rare earth zirconate (Ln2Zr2O7, Ln = La, Nd, Sm, and Gd) pyrochlore were studied by the Debye and quasi harmonic approximation combined with the first principles calculations. The difference between CV and CP was obtained. The temperature dependence of thermal expansions is mainly caused by the restoration of thermal energy due to phonon excitations at relatively a low temperature. When the temperature is much higher than Debye temperature, i.e., above 600 K for Ln2Zr2O7 compounds, the volumetric coefficient is increased linearly by increasing the temperature. The calculations are in good agreement with the experiments.
42 citations
TL;DR: In this article, the electronic, optical and thermodynamic properties of zinc-blende (ZB) and wurtzite (WZ) structures were investigated by using the plane-wave pseudopotential density functional theory (DFT).
Abstract: The electronic, optical and thermodynamic properties of ZnS in the zinc-blende (ZB) and wurtzite (WZ) structures are investigated by using the plane-wave pseudopotential density functional theory (DFT). The results obtained are consistent with other theoretical results and the available experimental data. When the pressures are above 20.5 and 27 GPa, the ZB-ZnS and the WZ-ZnS are converted into indirect gap semiconductors, respectively. The critical point structure of the frequency-dependent complex dielectric function is investigated and analysed to identify the optical transitions. Moreover, the values of heat capacity CV and Debye temperature ? at different pressures and different temperatures are also obtained successfully.
41 citations
TL;DR: Using binomial coefficients, new, simple, and efficient algorithms are presented for the accurate and fast calculation of the heat capacity of solids depending on the Debye temperature as discussed by the authors, which yields compact, closed-form expressions which enable the straightforward calculation of a solids for arbitrary temperature values.
Abstract: Using binomial coefficients, new, simple, and efficient algorithms are presented for the accurate and fast calculation of the heat capacity of solids depending on the Debye temperature. As will be seen, the present formulation yields compact, closed-form expressions which enable the straightforward calculation of the heat capacity of solids for arbitrary temperature values. Finally, the algorithm is used to simulate the variation of the specific heat capacity with temperature of MgO and ZnO crystals. The results were compared with those reported in the literature and found to be in close agreement with those of other studies.
41 citations
TL;DR: In this article, a variational expression for the decay constant is formulated and evaluated for trial solutions of the Maxwellian form for the neutron spectrum, for small deviations from thermal equilibrium, an expression of the form proposed by von Dardel is obtained.
41 citations