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
TL;DR: In this paper, structural, electronic, elastic and thermodynamic properties of Ni2LaZ (Z, Sb and Bi) Heusler alloys based on rare earth element have been investigated using full-potential linear muffin-tin orbital (FP-LMTO) method within generalized gradient approximation (GGA) in the frame of density functional theory.
Abstract: Structural, electronic, elastic and thermodynamic properties of Ni2LaZ (Z = As, Sb and Bi) Heusler alloys based on rare earth element have been investigated using full-potential linear muffin-tin orbital (FP-LMTO) method within generalized gradient approximation (GGA) in the frame of density functional theory (DFT). By using total energy variations, the independent elastic constants and their pressure dependence have been determined. Also, anisotropic parameter (A), shear modulus (G), Young modulus (E), Poisson’s ratio (ν), ratio (B/G) are calculated. Using quasi-harmonic Debye model, thermodynamic properties of Ni2LaZ (Z = As, Sb and Bi) Heusler alloys are investigated in temperature range 0–1200 K and pressure range 0–50 GPa. The temperature and pressure effects on the unit cell volume, bulk modulus (B), heat capacities (Cv) at stable volume, (Cp), Debye temperatures (θD), Gibbs energies (G), thermal expansion coefficients (α) and entropies (S) are determined from non-equilibrium Gibbs functions. This study allows to understand deeply the structural and thermodynamic properties of Ni2LaZ (Z = As, Sb and Bi) Heusler alloys in shortest time and cost-effective.
109 citations
TL;DR: In this article, the frequency spectrum of a face-centered cubic crystal lattice is found by actually modeling the constant-frequency surfaces of the secular determinant in plaster of Paris and measuring the volume enclosed between successive surfaces.
Abstract: The frequency spectrum of a face-centered cubic crystal lattice is found by actually modeling the constant-frequency surfaces of the secular determinant in plaster of Paris and measuring the volume enclosed between successive surfaces. The frequency spectrum so obtained is used in the evaluation of the specific heat of a general crystal of the type treated, and numerical values are presented for the element silver. The present theory (that of Born and v. Karman) is in much better agreement with experimental values for temperatures below 100°K than is the Debye theory. Certain anomalies in the specific heat curves of silver and potassium chloride at temperatures below 10°K are not explicable in terms of the atomic model that is used.
108 citations
TL;DR: In this article, the authors presented a model calculation of the thermal conductivity of germanium nitride, silicon nitride and carbon nitride in a temperature range in which intrinsic phonon scattering is dominant.
Abstract: We present a model calculation of the thermal conductivity of germanium nitride, silicon nitride, and carbon nitride in a temperature range in which intrinsic phonon scattering is dominant. We show that, in spite of the rather complex crystal structure of these nitrides, thermal conductivities exceeding 100 W m−1 K−1 can be attained in some of these compounds due to the combination of high Debye temperature and small Gruneisen constant.
108 citations
TL;DR: In this paper, the free exciton energy in the photoluminescence spectra taken at different temperatures and for two laser light intensities was analyzed using the Manoogian-Wooley (M-W) equation; by comparing them with the expression proposed by Vina; and using Varshni's expression for temperature variation of the band gap energy.
107 citations
TL;DR: In this article, the transport and magnetic properties of high-quality, sub-millimeter-sized (MgB) single crystals with clear hexagonal-plate shapes were reported. And the Debye temperature of MgB was obtained from the zero-field resistance curve, suggesting that the normal state transport properties are dominated by electron-phonon interactions.
Abstract: We report measurements of the transport and the magnetic properties of high-quality, sub-millimeter-sized ${\mathrm{MgB}}_{2}$ single crystals with clear hexagonal-plate shapes. The low-field magnetization and the magnetic hysteresis curves show the bulk pinning of these crystals to be very weak. The Debye temperature of ${\ensuremath{\Theta}}_{D}\ensuremath{\sim}1100 \mathrm{K},$ obtained from the zero-field resistance curve, suggests that the normal-state transport properties are dominated by electron-phonon interactions. The resistivity ratio between 40 K and 300 K was about 5, and the upper critical field anisotropy ratio was $3.0\ifmmode\pm\else\textpm\fi{}0.2$ at temperatures around 32 K.
107 citations