scholarly journals First-principles prediction of structure, energetics, formation enthalpy, elastic constants, polarization, and piezoelectric constants of AlN, GaN, and InN: Comparison of local and gradient-corrected density-functional theory

2001 ◽  
Vol 64 (4) ◽  
Author(s):  
Agostino Zoroddu ◽  
Fabio Bernardini ◽  
Paolo Ruggerone ◽  
Vincenzo Fiorentini
Keyword(s):  
Density Functional Theory ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Formation Enthalpy ◽  
Functional Theory ◽  
Piezoelectric Constants

First-principles study of the structural and elastic properties of Ti5Si3 with substitutions Zr, V, Nb, and Cr

2010 ◽  
Vol 25 (12) ◽  
pp. 2317-2324 ◽  
Author(s):  
Hui-Yuan Wang ◽  
Wen-Ping Si ◽  
Shi-Long Li ◽  
Nan Zhang ◽  
Qi-Chuan Jiang
Keyword(s):  
Density Functional Theory ◽  
Elastic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Elastic Moduli ◽  
Site Occupancy ◽  
Formation Enthalpy ◽  
Functional Theory ◽  
The Density Functional Theory

The formation enthalpy, electronic structures, and elastic moduli of the intermetallic compound Ti5Si3 with substitutions Zr, V, Nb, and Cr are investigated by using first-principles methods based on the density-functional theory. Our calculation shows that the site occupancy behaviors of alloying elements in Ti5Si3, determined by their atom radius, are consistent with the available experimental observations. Furthermore, using the Voigt–Reuss–Hill (VRH) approximation method, we obtained the bulk modulus B, shear modulus G, and the Young’s modulus E. Among these four substitutions, the V, Nb, and Cr substitutions can improve the ductility of Ti5Si3 effectively, while Zr substitution has little effect on the elastic properties of Ti5Si3. The elastic property variations of Ti5Si3 due to different substitutions are found to be correlated with the Me4d–Me4d antibonding and the strengthened Me4d–Si bonding in the solids.

First-Principles Investigation of the Site Occupancy and Elastic Properties of Y in γ-Co3(Al,W)

2014 ◽  
Vol 788 ◽  
pp. 473-476
Author(s):  
Qiang Yao ◽  
Yan Wang ◽  
Yu Hong Zhu ◽  
Xiao Lin Zhu
Keyword(s):  
Density Functional Theory ◽  
Elastic Constants ◽  
Phase Stability ◽  
First Principles ◽  
Density Functional ◽  
Site Occupancy ◽  
Heat Of Formation ◽  
Applied Strain ◽  
First Principles Calculations ◽  
Functional Theory

Site occupancy of Y in the γ′-Co3(Al,W) was predicted theoretically by first-principles calculations based on density functional theory. By computing total energy as a function of applied strain, the elastic constants of quaternary Co3(Al,W) were also predicted. The results suggest that Y preferentially occupies the W sites in Co3(Al,W). The calculation of heat of formation shows that the occupancy of Y on the W sites decreases the phase stability of Co3(Al,W). The theoretical calculation also shows that the L12 Co24Al4W3Y compound is ductile in nature.

Site Preference and Elastic Properties of 3d Transition Metals Alloying Addition in Ductility YAg Alloys

2012 ◽  
Vol 535-537 ◽  
pp. 1000-1004
Author(s):  
Yu Rong Wu ◽  
Wang Yu Hu ◽  
Long Shan Xu
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Transition Metals ◽  
Elastic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Alloying Elements ◽  
Site Preference ◽  
Functional Theory

First-principles supercell calculations based on density functional theory were performed to study the site preference behavior and elastic properties of 3d (Ti-Cu) transition-metal elements in B2 ductility YAg alloy. It is found that Ti occupies the Y sublattice, while V, Cr, Co, Fe, Ni and Cu tend to substitute for Ag site. All alloying elements can decrease the lattice parameters of Y8Ag8, among which Y7Ag8Ti shows the largest change. Furthermore, the calculated elastic constants show that Cr, Fe, Co and Cu can improve the ductility of YAg alloy, and Y8Ag7Fe presents the most ductility among these alloy, while Ti and Ni alloying elements reduce the ductility of YAg alloy, especially, V transforms ductile into brittle for YAg alloy. In addition, both V and Ni can increase the hardness of YAg alloy, and Y8Ag7V is harder than Y8Ag7Ni.

Site Preference and Elastic Properties of 5d Transition Metals in Ductility YAg Alloys

2012 ◽  
Vol 472-475 ◽  
pp. 1397-1401
Author(s):  
Yu Rong Wu ◽  
Wang Yu Hu ◽  
Long Shan Xu
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Transition Metals ◽  
Elastic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Site Preference ◽  
Alloying Element ◽  
Functional Theory

First-principles supercell calculations, which are based on density functional theory, were performed to study the site preference behavior and elastic properties of 5d (Hf-Au) transition-metal elements in B2 ductility YAg alloy. It is found that all alloying elements Hf, Ta, W, Re, Os, Ir, Pt and Au occupy the Y sub-lattice. Micro-alloying transition metals W, Re, Os, Ir and Pt decrease the lattice parameters of Y8Ag8 except Hf, Ta and Au, among which Y8Ag7Hf shows the largest variance. Furthermore, the calculated elastic constants show that Hf, Ta, W, Re, Os, Pt and Au improve the ductility of YAg alloy, and Y8Ag7Hf presents the most ductility among these alloy, while Ir transforms ductile into brittle for YAg alloy. In addition, Os alloying element increases the hardness of YAg alloy.

The Damping Term, from First Principles

2017 ◽  
Author(s):  
Olle Eriksson ◽  
Anders Bergman ◽  
Lars Bergqvist ◽  
Johan Hellsvik
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Spin Dynamics ◽  
Damping Term ◽  
Functional Theory ◽  
Basic Principles ◽  
Sham Equation ◽  
Damping Parameter ◽  
Simulation Cell

In the previous chapters we described the basic principles of density functional theory, gave examples of how accurate it is to describe static magnetic properties in general, and derived from this basis the master equation for atomistic spin-dynamics; the SLL (or SLLG) equation. However, one term was not described in these chapters, namely the damping parameter. This parameter is a crucial one in the SLL (or SLLG) equation, since it allows for energy and angular momentum to dissipate from the simulation cell. The damping parameter can be evaluated from density functional theory, and the Kohn-Sham equation, and it is possible to determine its value experimentally. This chapter covers in detail the theoretical aspects of how to calculate theoretically the damping parameter. Chapter 8 is focused, among other things, on the experimental detection of the damping, using ferromagnetic resonance.

scholarly journals Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

2021 ◽  
Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov
Keyword(s):  
Density Functional Theory ◽  
Double Layer ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Single Layer ◽  
Phonon Interaction ◽  
Functional Theory ◽  
Electron Phonon Interaction ◽  
The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

Adsorption of the Gas Molecules (NH3, C2H6O, C3H6O, CO, H2S) on noble metal (Ag, Au, Pt, Pd, Ru)–Doped MoSe2 Monolayer: A First-Principles Study

2021 ◽  
Author(s):  
Lanjuan Zhou ◽  
Sujing Yu ◽  
Yan Yang ◽  
Qi Li ◽  
Tingting Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Noble Metal ◽  
First Principles ◽  
Density Functional ◽  
Noble Metals ◽  
Gas Sensing ◽  
Functional Theory ◽  
First Principles Study ◽  
Gas Molecules ◽  
Sensing Performance

In this paper, the effects of five noble metals (Au, Pt, Pd, Ag, Ru) doped MoSe2 on improving gas sensing performance were predicted through density functional theory (DFT) based on...

Geometric, electronic properties of Au$_l$Pt$_m$ ($l$+$m$$\leqslant$10) clusters: A first-principles study

2021 ◽  
Author(s):  
Wei-Feng Xie ◽  
Hao-Ran Zhu ◽  
Shi-Hao Wei
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Inverse Design ◽  
Functional Theory ◽  
First Principles Study

The structural evolutions and electronic properties of Au$_l$Pt$_m$ ($l$+$m$$\leqslant$10) clusters are investigated by using the first$-$principles methods based on density functional theory (DFT). We use Inverse design of materials by...

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