DFT study of electronic and thermodynamic properties of gold-rich intermetallic compounds, Ce2Au2Cd and CeAu4Cd2

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jyoti Sagar ◽  
Reetu Singh ◽  
Vijay Kumar ◽  
Sanjay Kumar ◽  
Manish P. Singh ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Mechanical Strength ◽  
Intermetallic Compounds ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Debye Model ◽  
Effect Of Temperature ◽  
Mechanical Resistance ◽  
Electronic Band ◽  
High Mechanical Strength

Abstract Gold-rich rare earth intermetallic compounds (viz. Ce2Au2Cd and CeAu4Cd2) show unusual magnetic and physical properties, and they have extensive applications in electronic and mechanical industries due to their good electronic and thermal behavior with high mechanical strength. In the present research article, to take full advantage of technological importance of these materials, we have investigated the structural, electronic and thermodynamic properties of Ce2Au2Cd and CeAu4Cd2 ternary intermetallic compounds using density functional theory (DFT). The electronic band structure and density of state calculations show that Ce-f orbital electrons provide metallic character to both the compounds with strong hybridization of Au-p and Cd-p orbitals at the Fermi level. The effect of temperature has been studied on the various thermodynamic parameters using the quasi-harmonic Debye model. Thermodynamic properties show that CeAu4Cd2 compound has larger mechanical resistance (or high mechanical strength or hardness) and smaller randomness compared to Ce2Au2Cd with respect to temperature.

Electronic structure, optical and thermodynamic properties of ternary hydrides MBeH3 (M = Li, Na, and K)

2016 ◽  
Vol 94 (9) ◽  
pp. 865-876 ◽  
Author(s):  
Dj Guendouz ◽  
Z. Charifi ◽  
H. Baaziz ◽  
T. Ghellab ◽  
N. Arikan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Thermodynamic Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Debye Model ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Electron Charge Density ◽  
Principal Aspect

Electronic band structure, optical and thermodynamic properties of ternary hydrides MBeH3 (M = Li, Na, and K) were studied using ab initio density functional theory (DFT). The effect of the adopted approximation to the exchange-correlation functional of the DFT is explicitly investigated by considering four different expressions of two different classes (local-density approximation and generalized-gradient approximation). The calculated magnitude of B classifies MBeH3 (M = Li, Na, and K) as easily compressible materials. The bonding interaction in these compounds is quite complicated. The interaction between M and BeH6 is ionic and that between Be and H comprises both ionic and covalent characters. The electronic structure of the complex hydride was investigated by calculating the partial and total densities of states, and electron charge density distribution. Large gaps in the density of states appear at the Fermi energy of LiBeH3, NaBeH3, and KBeH3 indicating that these classes of hydrides are insulators. Optical properties, including the dielectric function, reflectivity, and absorption coefficient, each as a function of photon energy, are calculated and show an optical anisotropy for LiBeH3 and KBeH3. Through the quasi-harmonic Debye model, in which the phononic effects are considered, temperature dependence of volume V(T), bulk modulus B(T), and thermal expansion coefficient α(T), constant-volume and constant-pressure specific heat (Cv and Cp) and Debye temperature ΘD, the entropy S, and the Grüneisen parameter γ were calculated at wide pressure and temperature ranges. The principal aspect of the obtained results is the close similarity of MBeH3 (M = Li, Na, and K) compounds.

scholarly journals Structural, Electronic, Magnetic, Mechanic and Thermodynamic Properties of the Inverse Heusler Alloy Ti2NiIn Under Pressure

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 429 ◽  
Author(s):  
Tie Yang ◽  
Jieting Cao ◽  
Xiaotian Wang
Keyword(s):  
Thermodynamic Properties ◽  
Heusler Alloy ◽  
Density Functional ◽  
Mechanical Stability ◽  
Electronic Band Structure ◽  
Debye Model ◽  
Half Metallicity ◽  
Electronic Band ◽  
Functional Theory ◽  
Valence Electrons

Structural, electronic, magnetic and mechanic properties of the inverse Heusler alloy Ti2NiIn under different pressure are systematically studied with density functional theory (DFT). The equilibrium lattice constant and electronic band structure at null pressure are obtained to be consistent with previous work. Under currently applied static pressure from 0 GPa to 50 GPa, it is found that the half-metallicity of the material is maintained and the total magnetic moment (Mt) is kept at 3 µB, which obeys the Slater–Pauling rule, Mt = Zt − 18, where Zt is the total number of valence electrons. Besides, the effect of the tetragonal distortion was studied and it is found that the magnetic property of Ti2NiIn is almost unchanged. Several mechanical parameters are calculated including three elastic constants, bulk modulus B, Young’s modulus E, and shear modulus S and the mechanical stability is examined accordingly. Furthermore, the thermodynamic properties, such as the heat capacity CV, the thermal expansion coefficient α, the Grüneisen constant γ and the Debye temperature ΘD, are computed by using the quasi-harmonic Debye model within the same pressure range at a series of temperature from 0 to 1500 K. This theoretical study provides detailed information about the inverse Heusler compound Ti2NiIn from different aspects and can further lead some insight on the application of this material.

Structural, electronic and elastic properties of the B2-ScM (M =Au, Hg and Tl) intermetallic compounds: Ab initio calculations

2015 ◽  
Vol 04 (04) ◽  
pp. 1550020
Author(s):  
Ahmad A. Mousa ◽  
Jamil M. Khalifeh
Keyword(s):  
Mechanical Properties ◽  
Bulk Modulus ◽  
Intermetallic Compounds ◽  
Elastic Constants ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Full Potential ◽  
Generalized Gradient ◽  
Electronic Band

Structural, electronic, elastic and mechanical properties of ScM (M[Formula: see text][Formula: see text][Formula: see text]Au, Hg and Tl) intermetallic compounds are studied using the full potential-linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT), within the generalized gradient approximation (GGA) and the local density approximation (LDA) to the exchange-correlation approximation energy as implemented in the Wien2k code. The ground state properties including lattice parameters, bulk modulus and elastic constants were all computed and compared with the available previous theoretical and experimental results. The lattice constant was found to increase in contrast to the bulk modulus which was found to decrease with every substitution of the cation (M) starting from Au till Tl in ScM. Both the electronic band structure and density-of-states (DOS) calculations show that these compounds possess metallic properties. The calculated elastic constants ([Formula: see text], [Formula: see text] and [Formula: see text] confirmed the elastic stability of the ScM compounds in the B2-phase. The mechanical properties and ductile behaviors of these compounds are also predicted based on the calculated elastic constants.

BAND STRUCTURE, HARDNESS, THERMODYNAMIC AND OPTICAL PROPERTIES OF SUPERCONDUCTING Nb2AsC, Nb2InC AND Mo2GaC

2013 ◽  
Vol 02 (02) ◽  
pp. 1350007 ◽  
Author(s):  
M. A. HADI ◽  
M. S. ALI ◽  
S. H. NAQIB ◽  
A. K. M. A. ISLAM
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Vickers Hardness ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Population Analysis ◽  
Debye Model ◽  
Electronic Band ◽  
Specific Heats ◽  
First Time

First-principles investigation of the geometry, electronic band structure, Vickers hardness, thermodynamic and optical properties of three superconducting MAX compounds Nb 2 AsC , Nb 2 InC and Mo 2 GaC have been carried out by the plane-wave pseudopotential method based on density functional theory (DFT) implemented in the CASTEP code. The theoretical Vickers hardness has been studied by means of Mulliken bond population analysis and electronic densities of states. The thermodynamic properties such as the temperature and pressure dependent bulk modulus, Debye temperature, specific heats and thermal expansion coefficient of the three 211 MAX phases are derived from the quasi-harmonic Debye model with phononic effect for the first time. Furthermore, all the optical properties are determined and analyzed for the first time for two different polarization directions. The theoretical findings are compared with relevant experiments (where available) and the various implications are discussed in details.

scholarly journals Electronic band structure, optical, dynamical and thermodynamic properties of cesium chloride (CsCl) from first-principles

2015 ◽  
Vol 6 ◽  
pp. A7 ◽  
Author(s):  
Suat Bingol ◽  
Bahattin Erdinc ◽  
Harun Akkus
Keyword(s):  
Thermodynamic Properties ◽  
Band Structure ◽  
Density Of States ◽  
Ground State ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Cesium Chloride ◽  
Total Density ◽  
Electronic Band ◽  
Ground State Properties

The geometric structural optimization, electronic band structure, total density of states for valence electrons, density of states for phonons, optical, dynamical, and thermodynamical features of cesium chloride have been investigated by linearized augmented plane wave method using the density functional theory under the generalized gradient approximation. Ground state properties of cesium chloride are studied. The calculated ground state properties are consistent with experimental results. Calculated band structure indicates that the cesium chloride structure has an indirect band gap value of 5.46 eV and is an insulator. From the obtained phonon spectra, the cesium chloride structure is dynamically stable along the various directions in the Brillouin zone. Temperature dependent thermodynamic properties are studied using the harmonic approximation model.

Electronic structure, Mechanical and Thermodynamic properties of CoYSb (Y= Cr, Mo, W) half-Heusler compounds as potential spintronic materials

2021 ◽  
Author(s):  
O. T. Uto ◽  
J. O. Akinlami ◽  
S. Kenmoe ◽  
G. A. Adebayo
Keyword(s):  
Thermodynamic Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Heusler Alloys ◽  
Ferromagnetic State ◽  
Stable Phase ◽  
Type I ◽  
Electronic Density ◽  
Electronic Band ◽  
Half Metallic

Abstract We used Density Functional Theory (DFT) calculations to investigate the structural, electronic, magnetic, mechanical and thermodynamic properties of CoYSb (Y = Cr, Mo and W) compounds. These are XYZ type half-Heusler alloys, which also exist in the face centred cubic MgAgAs-type structure and conform to F¯43m space group. We computed these properties in three different atomic arrangements known as Type-I, Type-II and Type-III phases. In all these phases, the alloys were found to be in the ferromagnetic state. Furthermore, the calculated electronic band structure and the total electronic density of states indicated a metallic behaviour in CoWSb, nearly half-metallic in CoMoSb and half-metallic in CoCrSb, with a minority-spin band gap of 0.81 eV. Furthermore, the calculated mechanical properties predicted an anisotropic behaviour of these alloys in their stable phase. Finally, due to its high Debye temperature value, CoCrSb shows stronger covalent bonding than CoMoSb and CoWSb, respectively.

Theoretical Prediction of the Structural, Elastic, Electronic and Thermodynamic Properties of Binary CoP3 and Ternary FeCoP3 Skutterudites Materials

SPIN ◽  
2020 ◽  
Vol 10 (02) ◽  
pp. 2050011
Author(s):  
Riadh Zouablia ◽  
Ghlamallah Benabdellah ◽  
Mohamed Mokhtari ◽  
Said Hiadsi
Keyword(s):  
Thermodynamic Properties ◽  
Ternary Alloy ◽  
Electronic Band Structure ◽  
Binary Compound ◽  
Debye Model ◽  
Band Structure Calculation ◽  
Full Potential ◽  
Pressure Derivative ◽  
Electronic Band ◽  
The Impact

The structural, elastic, electronic and thermodynamic properties of skutterudite binary compound CoP3 and the ternary alloy FeCoP3 were investigated by using the full-potential linearized augmented plane-wave plus local orbitals method within the approximation GGA-PBEsol functional. The computed lattice constants, bulk moduli and the pressure derivative of the bulk moduli at the equilibrium are in good agreement with the published experimental data. The brittleness and ductility of these materials were studied by the analysis of the elastic constants and other mechanical parameters, where we have found that both CoP3 and FeCoP3 are ductile materials. The electronic band structure calculation, using the modified Becke-Johnson potential (TB-mBJ), shows that the skutterudite binary compound CoP3 at equilibrium, present a narrow indirect bandgap of 0.524[Formula: see text]eV where the ternary alloy FeCoP3 is a metal behavior. Finally, we investigated the impact of pressure [Formula: see text] and temperature [Formula: see text] on the lattice parameters, heat capacities [Formula: see text], Debye temperatures [Formula: see text] and the entropies [Formula: see text] using the quasi-harmonic Debye model.

The mechanical and thermodynamic properties of ZrAl2 under pressure from first-principles investigation

2016 ◽  
Vol 27 (01) ◽  
pp. 1650001
Author(s):  
Ning Wei ◽  
Xuefei Wang ◽  
Xuzhong Zuo
Keyword(s):  
Heat Capacity ◽  
High Pressure ◽  
Thermodynamic Properties ◽  
Debye Temperature ◽  
First Principles ◽  
Density Functional ◽  
Applied Pressure ◽  
Debye Model ◽  
Effect Of Temperature ◽  
Expansion Formula

The mechanical and thermodynamic properties of ZrAl2 alloy under high pressure are investigated by first-principles based on the density functional theory. Due to all the elastic constants of ZrAl2 alloy satisfy generalized stabilities criteria, ZrAl2 is mechanically stable under pressure up to 100[Formula: see text]GPa. By analyzing the value of B/G and Poisson’s ratio [Formula: see text] which are correlated with the ductility and brittleness of material, we found that ZrAl2 belongs to brittle material at pressure of 0–70[Formula: see text]GPa and will change from brittleness to ductility at 70[Formula: see text]GPa. Combining with high bulk modulus B and shear modulus G, the mechanical of properties will be improved under high pressure. Moreover, the thermodynamic properties, such as the Debye temperature [Formula: see text], heat capacity [Formula: see text] and thermal expansion [Formula: see text], are discussed using the quasi-harmonic Debye model. We noted that the Debye temperature [Formula: see text] is mainly dependent on the pressure and the effect of temperature on the heat capacity [Formula: see text] is more important than the applied pressure.

ELECTRONIC BAND STRUCTURE, OPTICAL, THERMAL AND BONDING PROPERTIES OF XMg2O4(X = Si, Ge) SPINEL COMPOUNDS

2013 ◽  
Vol 27 (18) ◽  
pp. 1350082 ◽  
Author(s):  
F. SEMARI ◽  
T. OUAHRANI ◽  
H. KHACHAI ◽  
R. KHENATA ◽  
M. RABAH ◽  
...  
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Theoretical Data ◽  
Debye Model ◽  
Ionic Character ◽  
Full Potential ◽  
Electronic Band ◽  
Spinel Compounds ◽  
Bonding Properties

Bonding nature as well as structural, optoelectronic and thermal properties of the cubic X Mg 2 O 4(X = Si , Ge ) spinel compounds have been calculated using a full-potential augmented plane-wave plus local orbitals (FP-APW+lo) method within the density functional theory. The exchange-correlation potential was treated with the PBE-GGA approximation to calculate the total energy. Moreover, the modified Becke–Johnson potential (TB-mBJ) was also applied to improve the electronic band structure calculations. The computed ground-state parameters (a, B, B′ and u) are in excellent agreements with the available theoretical data. Calculations of the electronic band structure and bonding properties show that these compounds have a direct energy band gap (Γ-Γ) with a dominated ionic character and the TB-mBJ approximation yields larger fundamental band gaps compared to those obtained using the PBE-GGA. Optical properties such as the complex dielectric function ε(ω), reflectivity R(ω) and energy loss function L(ω), for incident photon energy up to 40 eV, have been predicted. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the effects of pressure P and temperature T on the thermal expansion coefficient, Debye temperature and heat capacity for the considered compounds are investigated for the first time.

Effect of Temperature/Pressure on Lattice Dynamics of FeNi

2016 ◽  
Vol 1141 ◽  
pp. 84-90 ◽  
Author(s):  
N.Y. Pandya ◽  
A.D. Mevada ◽  
P.N. Gajjar
Keyword(s):  
Density Of States ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Electronic Band Structure ◽  
Effect Of Temperature ◽  
Electronic Band ◽  
Functional Theory ◽  
Phonon Dispersion Curves ◽  
Consistent Method ◽  
Hard Ferromagnet

Tetratenite phase of L10 (CuAu) FeNi is identified as a hard ferromagnet in spite of that common FeNi alloys are classified as a soft magnet. Due to its strong magnetic anisotropy and large coercivity, tetrataenite phase of L10 FeNi is under investigation as a rare earth free advanced permanent magnet. Our computed equilibrium lattice constant and c/a ratio for tetratenite phase of L10 (CuAu) FeNi are in 10 % deviation with the other available results. The vibrational and electronic properties of L10 FeNi at finite temperatures/pressures are studied using the first-principles plane wave self-consistent method under the framework of density functional theory. Conclusions based on the phonon dispersion curves, phonon density of states and electronic band structure along with total and projected density of states at finite temperatures/pressures are outlined.

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