Atomistic Simulation and Density Functional Analysis of Ni(111)-ZrO2(100)(Cubic) and NiO(111)-Ni(111)-ZrO2(100)(Cubic) Interfaces

2000 ◽  
Vol 654 ◽  
Author(s):  
Chang-Xin Guo ◽  
Donald E. Ellis ◽  
Vinayak P. Dravid ◽  
Luke Brewer
Keyword(s):  
First Principles ◽  
Atomistic Simulation ◽  
Density Functional ◽  
Depth Profiling ◽  
Interface Plane ◽  
Functional Theory ◽  
Spatially Resolved ◽  
Microscopy Data ◽  
Energy Profiling ◽  
Good Agreement

AbstractThe atomic arrangement and electronic structure in the vicinity of Ni(111)- ZrO2(100)(Cubic) and NiO(111)-Ni(111)-ZrO2(100)(Cubic) interfaces have been studied by atomistic simulation and by first-principles Density Functional theory. “Depth Profiling” is carred out in both methodologies, to determine modifications of cohesive energy and electron distribution of atomic layers from the interface plane. The energy profiling results show the interface consists of only a few atomic layers. Simulation results and electron density analyses are in good agreement with High Resolution Spatially Resolved Electron Microscopy data.

Hydrogen Isotopic Effects of Uranium Hydrides: First-Principles Calculations

2015 ◽  
Vol 817 ◽  
pp. 675-684 ◽  
Author(s):  
Hai Yan Lu
Keyword(s):  
Raman Spectrum ◽  
First Principles ◽  
Density Functional ◽  
Coulomb Repulsion ◽  
Local Spin Density Approximation ◽  
Functional Theory ◽  
Lattice Constants ◽  
Isotopic Effects ◽  
Typical Frequency ◽  
Good Agreement

In this paper, we study the ground-state and lattice dynamical properties of β-UH--3by means of the first-principles density functional theory within the local spin-density approximation (LSDA)+Uformulism. The lattice constants and electronic structure are correctly described by taking into account the strong on-site Coulomb repulsion among the 5felectrons localized on uranium atoms. Good agreement with experiments is achieved by tuning the effective Hubbard parameter at around 4 eV. The phonon band structure confirms the dynamical stability of β-UH--3, and the Raman-active modes are consistent with Raman spectrum measurements. The substitution of the deuterium (tritium) atom for hydrogen atom makes significant variations in the typical frequency of Raman-active modes. It is found that the Raman-active mode frequency is approximately inversely proportional to the square root of the hydrogen isotope mass. We conclude that Raman spectrum provides a powerful method for detecting hydrogen isotopic effects.

scholarly journals First-principles study on electronic, optic, elastic, dynamic and thermodynamic properties of RbH compound

2015 ◽  
Vol 6 ◽  
pp. A6 ◽  
Author(s):  
Sinem Erden Gulebaglan ◽  
Emel Kilit Dogan ◽  
Mehmet Nurullah Secuk ◽  
Murat Aycibin ◽  
Bahattin Erdinc ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Band Gap ◽  
Lattice Constant ◽  
First Principles ◽  
Density Functional ◽  
Temperature Dependent ◽  
Functional Theory ◽  
Salt Structure ◽  
Elastic Lattice ◽  
Good Agreement

We performed first-principles calculations to obtain the electronic, optical, elastic, lattice-dynamical and thermodynamic properties of RbH compound with rock salt structure. The ground-state properties, i.e., the lattice constant and the band gap were investigated using a plane wave pseudopotential method within density functional theory. The calculated lattice constant, bulk modulus, energy band gap and elastic constants are reported and compared with previous theoretical and experimental results. Our calculated results and the previous results which are obtained from literature are in a good agreement. Moreover, real and imaginary parts of complex dielectric function, reflectivity spectrum, absorption, extinction coefficient and loss function as a function of photon energy and refractive index with respect to photon wavelength were calculated. In addition, temperature dependent thermodynamic properties such as Helmholtz free energy, internal energy, entropy and specific heat have been studied.

Composition and Strain Dependence of the Piezoelectric Coefficients in Semiconductor Alloys

2007 ◽  
Vol 1017 ◽  
Author(s):  
T. Hammerschmidt ◽  
M. A. Migliorato ◽  
D. Powell ◽  
A. G. Cullis ◽  
G. P. Srivastava
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Piezoelectric Coefficient ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Semiconductor Alloys ◽  
Binding Model ◽  
Functional Theory ◽  
Photo Current ◽  
Good Agreement

AbstractWe propose a tight-binding model for the polarization that considers direct and dipole contributions and employs microscopic quantities that can be calculated by first-principles methods, e.g. by employing Density Functional Theory (DFT). Applying our model to InxGa1-xAs alloys allows us to settle discrepancies between the values of e14 as obtained from experiments and from linear interpolations between the values of InAs and GaAs. Our calculated piezoelectric coefficient is in very good agreement with photo current measurements of InAs/GaAs(111) quantum well samples.

scholarly journals Effect of Doping on the Thermoelectric Properties of Thallium Tellurides Using First Principles Calculations

2011 ◽  
Vol 172-174 ◽  
pp. 985-989 ◽  
Author(s):  
Philippe Jund ◽  
Xiao Ma Tao ◽  
Romain Viennois ◽  
Jean Claude Tédenac
Keyword(s):  
Experimental Data ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Pure Compound ◽  
Functional Theory ◽  
Lattice Constants ◽  
Thallium Tellurides ◽  
Good Agreement

We present a study of the electronic properties of Tl5Te3, BiTl9Te6and SbTl9Te6compounds by means of density functional theory based calculations. The optimized lattice constants of the compounds are in good agreement with the experimental data. The band gap of BiTl9Te6and SbTl9Te6compounds are found to be equal to 0.589 eV and 0.538 eV, respectively and are in agreement with the available experimental data. To compare the thermoelectric properties of the different compounds we calculate their thermopower using Mott’s law and show, as expected experimentally, that the substituted tellurides have much better thermoelectric properties compared to the pure compound.

Theoretical calculations of stability, mechanical and thermodynamic properties of IVA group Willemite-II nitrides

2015 ◽  
Vol 14 (04) ◽  
pp. 1550024 ◽  
Author(s):  
Ying-Chun Ding ◽  
Min Chen ◽  
Wen-Juan Wu
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Mechanical Anisotropy ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Good Agreement

The structural stability and mechanical and thermodynamic properties of WII- A 3 N 4 ( A=C , Si , Ge and Sn ) are calculated by first-principles calculations based on the density functional theory. The calculated lattice parameters and elastic constants of WII- A 3 N 4 ( A=C , Si , Ge and Sn ) are in good agreement with the experimental data and previously calculated values. WII- A 3 N 4 ( A=C , Si , Ge and Sn ) compounds are also found to be thermodynamically and mechanically stable. The results suggest that hardness of WII- C 3 N 4 is the hardest of these C 3 N 4 polymorphs. The hardness of WII- Sn 3 N 4 is the smallest among WII- A 3 N 4 ( A=C , Si , Ge and Sn ). Furthermore, the mechanical anisotropy, Debye temperature, the minimum thermal conductivity and thermodynamic properties of WII- A 3 N 4 ( A=C , Si , Ge and Sn ) compounds can be investigated.

Electronic, Optical and Vibrational Properties of B3N3H6 from First-Principles Calculations

2021 ◽  
Author(s):  
Yun-Dan Gan ◽  
Han Qin ◽  
Fu-Sheng Liu ◽  
Zheng-Tang Liu ◽  
Cheng lu Jiang ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Vibrational Properties ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Conductivity Loss ◽  
Good Agreement

Abstract The electronic, optical and vibrational properties of B3N3H6 have been calculated by means of first-principles density functional theory (DFT) calculations within the generalized gradient approximation (GGA) and the local density approximation (LDA). The calculated structural parameters of B3N3H6 are in good agreement with experimental work. With the band structure and density of states (DOS), we have analyzed the optical properties including the complex dielectric function, refractive index, absorption, conductivity, loss function and reflectivity. By the contrast, it is found that on the (001) component and (100) component have obvious optical anisotropy. Moreover, the vibrational properties have been obtained and analyzed.

First-principles study of intermetallic compounds In CrMnFeCoNiZr system high-entropy alloy

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744007
Author(s):  
Lei Zhang ◽  
Yi Xu ◽  
Xinggang Li
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Casting Process ◽  
High Entropy Alloy ◽  
Functional Theory ◽  
High Entropy ◽  
Calculation Results ◽  
Cohesive Energies ◽  
Strengthening Phases ◽  
Good Agreement

The structural properties, formation heats, cohesive energies, elastic properties and electronic structures of common intermetallics in CrMnFeCoNiZr system high-entropy alloys are analyzed by using density functional theory. The calculation results show that Co1Zr1, Co2Zr1, Fe2Zr1 and Fe[Formula: see text]Zr6 phases may form in the casting process of the alloy, which indicates good agreement with the XRD results of the self-designed alloys. The calculated elastic constants reveal that Co2Zr1, Fe2Zr1 and Fe[Formula: see text]Zr6 are mechanically stable. In addition, the results show that Co2Zr1, Fe2Zr1 and Fe[Formula: see text]Zr6 with high shear modulus and elastic modulus would be excellent strengthening phases in high-entropy alloy and would improve the hardness of the alloys.

scholarly journals First principles calculations of the electronic and dielectric properties of λ-Ta2O5

TecnoLógicas ◽  
2018 ◽  
Vol 21 (43) ◽  
pp. 43-52 ◽  
Author(s):  
Camilo Valencia-Balvín ◽  
Santiago Pérez-Walton ◽  
Jorge M. Osorio-Guillén
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Theoretical Study ◽  
Wide Bandgap ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Wide Bandgap Semiconductor ◽  
Exchange Correlation ◽  
Good Agreement

Ta2O5 is a wide-bandgap semiconductor that offers interesting applications in microwavecommunications, mainly related to the manufacture of filters and resonators whosesize is inversely proportional to the dielectric constant of the material. For that reason, inthis work we present a theoretical study, based on density functional theory (using PBEsoland hybrid HSE06 exchange-correlation functionals), of the electronic and dielectricproperties of the orthorhombic model -Ta2O5. We found that this model has a direct gap of2.09 and 3.7 eV with PBEsol and HSE06, respectively. Furthermore, the calculated staticdielectric constant, 51, is in good agreement with the reported values of other phases of thissemiconductor.

Ab initio study of optical and vibrational properties of Ni3C

2017 ◽  
Vol 31 (03) ◽  
pp. 1750003
Author(s):  
Mohammad Bagher Golivand ◽  
Arash Boochani ◽  
Arsalan Akhtar ◽  
Maryam Torkashvand ◽  
Nashmyl Karimian
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Infrared Region ◽  
Vibrational Properties ◽  
Optical Parameters ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Good Agreement

The structural, electronic, optical and vibrational properties of Ni3C have been studied by density functional theory (DFT) framework with first-principles study. The obtained structural parameters are in good agreement with other works. The electronic study demonstrates metallic behavior of Ni3C since it has no energy gap at Fermi level. The optical parameters such as real and imaginary dielectric functions, loss function, conductivity, reflection, refraction indexes and absorption coefficients are studied. The phonon investigations confirm that the Ni3C bulk is dynamically stable and carbon has a major role in optical spectrum of the material at infrared region. Finally, the [Formula: see text] behavior of [Formula: see text] at low temperatures is obtained, as expected.

First-Principles Study on the Elastic and Electronic Properties of 2H-CuGaO2

2013 ◽  
Vol 446-447 ◽  
pp. 3-7 ◽  
Author(s):  
Wen Ting Liu ◽  
Zheng Tang Liu
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Elastic Anisotropy ◽  
Anisotropy Ratio ◽  
Functional Theory ◽  
Indirect Band Gap ◽  
Calculated Equilibrium ◽  
Elastic Coefficients ◽  
Good Agreement

The structure, elastic and electronic properties of 2H-CuGaO2are calculated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density functional theory. The calculated equilibrium lattice parameters is in good agreement with experimental and reported values. The elastic coefficients, bulk, shear and Youngs modulus, Poissons ratio and elastic anisotropy ratio of 2H-CuGaO2were calculated. The electronic properties of 2H-CuGaO2have been calculated and the results show that 2H-CuGaO2has an indirect band gap.

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