Ab initio investigation of the electronic, lattice dynamic and thermodynamic properties of ScCd intermetallic alloy

2016 ◽  
Vol 30 (24) ◽  
pp. 1650175
Author(s):  
B. I. Adetunji ◽  
A. S. Olayinka ◽  
J. B. Fashae ◽  
V. C. Ozebo
Keyword(s):  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Density Of States ◽  
Specific Heat Capacity ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Harmonic Approximation ◽  
Generalized Gradient ◽  
Vibrational Free Energy

The electronic structures, lattice dynamics and thermodynamic properties of rare-earth intermetallic ScCd alloy are studied by the first-principles plane-wave pseudopotential method within the generalized gradient approximation in the framework of density functional pertubation theory. The band structure, density of states, phonon dispersion frequencies, vibrational free energy [Formula: see text], specific heat capacity [Formula: see text] and entropy are studied between 0 K and 1500 K. Finally, using the calculated phonon density of states, the thermodynamic properties are determined within the quasi-harmonic approximation and a value of 47.9 (J/mol⋅K) at 300 K for specific heat capacity of ScCd is predicted.

Ab Initio Study of the Phonon Frequency, Electrical and Thermal Properties of TiN

2012 ◽  
Vol 155-156 ◽  
pp. 291-297
Author(s):  
Xin Tan ◽  
Yu Qing Li ◽  
Xue Jie Liu
Keyword(s):  
Electronic Structure ◽  
Thermal Properties ◽  
Specific Heat ◽  
Density Functional ◽  
Correlation Energy ◽  
Phonon Dispersion ◽  
Harmonic Approximation ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Phonon Spectra

With a motivation to understand microscopic aspects of TiN relevant to the electronic structure, phonon and thermal properties of transition metal nitride TiN superlattices, we determine its electronic structure, phonon spectra and thermal properties using first-principles calculations based on density functional theory with a generalized gradient approximation of the exchange correlation energy. We find that the electronic bands crossed by EF are half occupied, TiN has the ability of taking part in chemical reactions and also has the surface activity; A large gap in its phonon spectra, anomalies in the phonon dispersion of metallic TiN, manifested as dips in acoustic branches, but it do not contain soft modes in any direction; The specific heat (Cv) of TiN rises rapidly at low temperatures, the Cv values of the material, is identical to the Dulong-Petit value at high temperatures. Under the quasi-harmonic approximation (QHA), the thermal expansion, specific heat and bulk modulus B(T) are obtained, and the B(T) decreases along with the increase of temperature.

scholarly journals Thermodynamics of Uranium Tri-Iodide from Density-Functional Theory

2020 ◽  
Vol 10 (11) ◽  
pp. 3914
Author(s):  
Per Söderlind ◽  
Aurélien Perron ◽  
Emily E. Moore ◽  
Alexander Landa ◽  
Tae Wook Heo
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Heat Capacity ◽  
Density Functional ◽  
Thermodynamic Assessment ◽  
Harmonic Approximation ◽  
Metallic System ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation

Density-functional theory (DFT) is employed to investigate the thermodynamic and ground-state properties of bulk uranium tri-iodide, UI3. The theory is fully relativistic and electron correlations, beyond the DFT and generalized gradient approximation, are addressed with orbital polarization. The electronic structure indicates anti-ferromagnetism, in agreement with neutron diffraction, with band gaps and a non-metallic system. Furthermore, the formation energy, atomic volume, crystal structure, and heat capacity are calculated in reasonable agreement with experiments, whereas for the elastic constants experimental data are unavailable for comparison. The thermodynamical properties are modeled within a quasi-harmonic approximation and the heat capacity and Gibbs free energy as functions of temperature agree with available calculation of phase diagram (CALPHAD) thermodynamic assessment of the experimental data.

Estimation of the heat capacity of CdTe semiconductor

2016 ◽  
Vol 30 (04) ◽  
pp. 1650026 ◽  
Author(s):  
Hüseyin Koç ◽  
Erhan Eser
Keyword(s):  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Binomial Coefficient ◽  
Debye Model ◽  
The Other ◽  
Temperature Range ◽  
Theoretical Results ◽  
Good Agreement

The aim of this paper is to provide a simple and reliable analytical expression for the thermodynamic properties calculated in terms of the Debye model using the binomial coefficient, and examine specific heat capacity of CdTe in the 300–1400 K temperature range. The obtained results have been compared with the corresponding experimental and theoretical results. The calculated results are in good agreement with the other results over the entire temperature range.

Thermodynamic Properties of Ionized Gases at High Temperatures

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Kian Eisazadeh-Far ◽  
Hameed Metghalchi ◽  
James C. Keck
Keyword(s):  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
High Temperatures ◽  
Mole Fraction ◽  
Specific Heat Capacity ◽  
Local Equilibrium ◽  
Equilibrium Conditions ◽  
New Model ◽  
Temperature Range

Thermodynamic properties of ionized gases at high temperatures have been calculated by a new model based on local equilibrium conditions. Calculations have been done for nitrogen, oxygen, air, argon, and helium. The temperature range is 300–100,000 K. Thermodynamic properties include specific heat capacity, density, mole fraction of particles, and enthalpy. The model has been developed using statistical thermodynamics methods. Results have been compared with other researchers and the agreement is good.

scholarly journals Modelling of size-dependent thermodynamic properties of metallic nanocrystals based on modified Gibbs–Thomson equation

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Manauwar Ali Ansari
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Debye Temperature ◽  
Melting Temperature ◽  
Specific Heat Capacity ◽  
Cohesive Energy ◽  
Size Dependent

AbstractIn this paper, a new theoretical two-phase (solid–liquid) type model of melting temperature has developed based on the modified Gibbs–Thomson equation. Further, it is extended to derive other different size-dependent thermodynamic properties such as cohesive energy, Debye temperature, specific heat capacity, the thermal and electrical conductivity of metallic nanoparticles. Quantitative calculation of the effect of size on thermodynamic properties resulted in, varying linearly with the inverse of characteristic length of nanomaterials. The models are applied to Al, Pb, Ag, Sn, Mo, W, Co, Au and Cu nanoparticles of spherical shape. The melting temperature, Debye temperature, thermal and electrical conductivity are found to decrease with the decrease in particle size, whereas the cohesive energy and specific heat capacity are increased with the decrease in particle size. The present model is also compared with previous models and found consistent. The results obtained with this model validated with experimental and simulation results from several sources that show similar trends between the model and experimental results. Graphic abstract

Study of the Structural, Dynamic and Thermodynamic Properties of the III- Antimonides Semiconductors

2021 ◽  
Vol 406 ◽  
pp. 250-255
Author(s):  
Sabrina Bounab ◽  
Abdelouahb Bentabet ◽  
Youssef Bouahadda
Keyword(s):  
Thermodynamic Properties ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Local Density ◽  
Harmonic Approximation ◽  
High Symmetry ◽  
Present Contribution ◽  
Structural Dynamic ◽  
Density Functional Perturbation Theory ◽  
Experimental Works

In the present contribution, structural, dynamic, and some thermodynamic properties of the III-Antimonides are studied using the density-functional perturbation theory (DFPT) within the local density approximation (LDA) in combination with the harmonic approximation Our results for the structural properties such as the lattice constant and the bulk modulus were found to agree well with the previous theoretical and experimental works. We have also calculated the phonon dispersion relation, and we found that our phonon calculations show that these compounds are dynamically stable in the zinc blende phase moreover our results of the optical and acoustic phonon frequencies at the high symmetry points Γ, X and L are in good agreement with the available theoretical and experimental data. In addition, the thermodynamic properties, including the free energy, internal energy, entropy, and the heat capacity at constant volume were predicted and discussed.

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