First-Principles Investigations of Structural Stability of LuN

2013 ◽  
Vol 690-693 ◽  
pp. 559-563 ◽  
Author(s):  
Xiao Cui Yang ◽  
En Jie Zhang ◽  
Hong Yuan Ma ◽  
Jun Ping Xiao
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Structural Stability ◽  
First Principles ◽  
Phonon Dispersion ◽  
Type Structure ◽  
First Principles Calculations ◽  
Phonon Dispersion Curves ◽  
Elevated Pressures ◽  
Cscl Type

An investigation on structural stability of LuN under high pressure has been conducted using first-principles calculations. At elevated pressures LuN is predicted to undergo a phase transition from NaCl-type structure (B1) into CsCl-type structure (B2). The predicted transition pressure is 220 GPa. The phonon dispersion curves of B1 and B2 at 0 and 220 GPa are presented.

First-Principles Calculations of Electronic and Structural Properties of LaN under High Pressure

2013 ◽  
Vol 331 ◽  
pp. 563-566 ◽  
Author(s):  
Xiao Cui Yang ◽  
Fang Liu ◽  
Xiang Yi Luo ◽  
Hong Yu Lin ◽  
Jun Ping Xiao
Keyword(s):  
High Pressure ◽  
First Principles ◽  
Density Functional ◽  
Structural Phase ◽  
Type Structure ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Elevated Pressures ◽  
Cscl Type ◽  
Valence Bands

An investigation on the electronic structures and structural stability of LaN under high pressure has been conducted using first-principles calculations based on density functional theory (DFT). At elevated pressures LaN is predicted to undergo a structural phase transition from NaCl-type to CsCl-type structure. The predicted transition pressure is 65 GPa. The result of elastic constants indicates that the NaCl-type structure is mechanically a stable structure and the CsCl-type strcture is not mechanically a stable one. The calculated band structure of LaN is semimetallic.the conduction and valence bands.

First-Principles Investigations on Electronic, Elastic and Thermodynamic Properties of VN under High Pressure

2012 ◽  
Vol 550-553 ◽  
pp. 2805-2809 ◽  
Author(s):  
Ai Min Hao ◽  
Xiao Cui Yang ◽  
Li Xin Zhang ◽  
Qi Zhou Zhang
Keyword(s):  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Density Functional ◽  
Structural Phase ◽  
Basis Set ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Elevated Pressures ◽  
Cscl Type

An investigation on electronic, elastic and thermodynamic properties of VN under high pressure has been conducted using first-principles calculations based on density functional theory (DFT) with the plane wave basis set as implemented in the CASTEP code. At elevated pressures VN is predicted to undergo a structural phase transition from the relatively open NaCl-type structure into the denser CsCl-type atomic arrangement. The predicted transition pressure is 189 GPa. The elastic constants, Debye temperature as a function of pressure and temperature of VN are presented.

Theoretical aspects in structural distortion and the electronic properties of lithium peroxide under high pressure

2018 ◽  
Vol 20 (14) ◽  
pp. 9488-9497 ◽  
Author(s):  
Pornmongkol Jimlim ◽  
Komsilp Kotmool ◽  
Udomsilp Pinsook ◽  
Suttichai Assabumrungrat ◽  
Rajeev Ahuja ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Electronic Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Structural Phase ◽  
Structural Distortion ◽  
First Principles Calculations ◽  
Lithium Peroxide

The structural phase transition and electronic properties of Li2O2 under pressures up to 500 GPa have been investigated using first-principles calculations.

Pressure effects on mechanical and electronic properties of metallic C14 by first-principles calculation

2019 ◽  
Vol 33 (18) ◽  
pp. 1950193
Author(s):  
Yingjiao Zhou ◽  
Qun Wei ◽  
Bing Wei ◽  
Ruike Yang ◽  
Ke Cheng ◽  
...  
Keyword(s):  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Pressure Range ◽  
Phonon Dispersion ◽  
Elastic Anisotropy ◽  
Acoustic Velocity ◽  
Pressure Effects ◽  
First Principles Calculation ◽  
First Principles Calculations

The elastic constants and phonon dispersion of metallic C[Formula: see text] are calculated by first-principles calculations. The results show that the metallic C[Formula: see text] is mechanically and dynamically stable under high pressure. The variations of G/B ratio, Poisson’s ratio, elastic anisotropy, acoustic velocity and Debye temperature at the pressure range from 0 GPa to 100 GPa are analyzed. The results reveal that by adjusting the pressures the elastic anisotropy and thermodynamic properties could be improved for better applicability.

Ab initio investigations of TlI-type compounds under high pressure

2004 ◽  
Vol 219 (6) ◽  
Author(s):  
Daniel Becker ◽  
Horst P. Beck
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Electron Pair ◽  
Elevated Pressure ◽  
Type Structure ◽  
Electronic Density ◽  
Structure Changes ◽  
Cscl Type ◽  
Wide Pressure Range ◽  
The Stability

AbstractIn this work, we present a theoretical study (based on DFT-calculations) in a wide pressure range of the structural and electronic properties and the stability of compounds crystallising in a TlI- or CrB-type structure. Both structure types have the characteristic structural feature of zigzag chains with unusual short homonuclear distances. The main focus of this study is to elucidate the nature of bonding within these zigzag chains at ambient and elevated pressure. For this purpose we discuss the evolution of the distances within the zigzag chains with pressure, the transition pressure of the phase transition to a CsCl-type arrangement (high-pressure phase) and compressibilities of the low- and high-pressure phases. For a better understanding of the structure and bonding, the band structures of these compounds are evaluated. The calculations are complemented by an orbital analysis using the crystal orbital Hamilton population (COHP) and an analysis of the electronic density topology with the electron localisation function (ELF). Our study indicates that there is a bonding electron pair in compounds crystallising in the CrB-type structure and that the nature of the electron pair does not change significantly at elevated pressure up to the phase transition. However, the “character” of the additional electron pair in the In-monohalides (TlI-type structure) changes with increasing pressure from nonbonding to bonding. The phase transition to a CsCl- type structure implies a fundamental change to nonbonding stereochemically inert electron pairs for all compounds.

Structural phase transition, electronic, elastic, and vibrational properties of LiAl intermetallic compound: insights from first-principles calculations

2017 ◽  
Vol 95 (8) ◽  
pp. 691-698
Author(s):  
Y. Mogulkoc ◽  
Y.O. Ciftci ◽  
G. Surucu
Keyword(s):  
Phase Transition ◽  
Density Of States ◽  
Structural Phase Transition ◽  
First Principles ◽  
Density Functional ◽  
Structural Phase ◽  
Type Structure ◽  
Vibrational Properties ◽  
First Principles Calculations ◽  
Electronic Band

Using the first-principles calculations based on density functional theory (DFT), the structural, elastic, electronic, and vibrational properties of LiAl have been explored within the generalized gradient approximation (GGA) using the Vienna ab initio simulation package (VASP). The results demonstrate that LiAl compound is stable in the NaTl-type structure (B32) at ambient pressure, which is in good agreement with the experimental results and there is a structural phase transition from NaTl-type structure (B32) to CsCl-type structure (B2) at around 22.2 GPa pressure value. The pressure effects on the elastic properties have been discussed and the elastic property calculation indicates that the elastic instability could provide a phase transition driving force according to the variations relation of the elastic constant versus pressure. To gain further information about this, we also have investigated the other elastic parameters (i.e., Zener anisotropy factor, Poisson’s ratio, Young’s modulus, and isotropic shear modulus). The electronic band structure, total and partial density of states, phonon dispersion curves, and one-phonon density of states of B2 and B32 phases are also presented with results.

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