First-Principles Calculation of the Vacancy Formation Energy in VC

2014 ◽  
Vol 887-888 ◽  
pp. 966-969 ◽  
Author(s):  
Shi Yang Sun ◽  
Ping Ping Xu ◽  
Xue Jie Liu ◽  
Xin Tan
Keyword(s):  
Density Functional ◽  
Formation Energy ◽  
Vanadium Carbide ◽  
Vacancy Concentration ◽  
Calculation Model ◽  
Vacancy Formation Energy ◽  
First Principles Calculation ◽  
Vacancy Formation ◽  
Functional Theory ◽  
Super Cell

The ab inttio density functional theory had been used to calculate the vacancy formation energy of C in the vanadium carbide, to reveal the effects of super-cell size and parameters k points. It turned out that,the calculation model of C vacancy formation energy in VC should be contain 64 atoms, while the K grid meshed 5x5x5 above using the Monkhorst-Pack method. And due to the vacancy formation energy of C 6.76eV, the high vacancy concentration of VC could be caused by simple thermal vibration. These researches not only had a certain value to know VC properties, but also had great significance to rediscover the forming of vacancy.

Calculation of vacancy-formation energy of alkali metals using an electron-density functional

1979 ◽  
Vol 22 (2) ◽  
pp. 205-207
Author(s):  
V. M. Kuznetsov ◽  
Yu. A. Khon ◽  
S. A. Beznosyuk ◽  
V. P. Fadin
Keyword(s):  
Electron Density ◽  
Density Functional ◽  
Alkali Metals ◽  
Formation Energy ◽  
Vacancy Formation Energy ◽  
Vacancy Formation

FIRST-PRINCIPLES CALCULATION OF LEAD-FREE PEROVSKITE SnTiO3

2013 ◽  
Vol 27 (24) ◽  
pp. 1350144 ◽  
Author(s):  
HONGJUN YE ◽  
RUIZHI ZHANG ◽  
DAWEI WANG ◽  
YU CUI ◽  
JIE WEI ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Formation Energy ◽  
Piezoelectric Materials ◽  
First Principles Calculation ◽  
Lead Free ◽  
Structure Stability ◽  
Functional Theory ◽  
Phonon Spectra ◽  
Sn Substitution

The phonon spectra, band structure and density of states of cubic perovskite SnTiO 3 were investigated using first-principles density functional theory (DFT) computation. The potential energy curves of cations displacement and the formation energy of Sn substitution to B-site were calculated to estimate the structure stability. The results indicate that perovskite SnTiO 3 is a promising ferroelectric end member for lead-free piezoelectric materials and applications.

First-Principles Calculation of Defect Formation and Positron Annihilation States in Bi2Te3

2017 ◽  
Vol 373 ◽  
pp. 41-45 ◽  
Author(s):  
Bin Zhao ◽  
Bo Zhou ◽  
Chong Yang Li ◽  
Ning Qi ◽  
Zhi Quan Chen
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Formation Energy ◽  
Defect Formation ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Rich Condition ◽  
The Density Functional Theory ◽  
Positron Wave Function ◽  
Positron Lifetimes

Defect formation energy in Bi2Te3 thermoelectric material was calculated using a first principles approach based on the Density Functional Theory (DFT). For vacancy-type defect, the Te1 vacancy (VTe1) is the most stable defect with low formation energy in both Bi-rich and Te-rich conditions, which indicates that the Te1 vacancies have higher probability to be formed. For antisite defects, the formation energy of BiTe1 is much lower than that of BiTe2 in Bi-rich condition, while in Te-rich condition it is beneficial for TeBi with lower formation energy. Positron wave function distribution and positron lifetimes of different annihilation states in Bi2Te3 were also calculated using the atomic superposition (ATSUP) method. The positron bulk lifetime in Bi2Te3 is about 231 ps, and for the neutral vacancy-type defects without relaxation, the positron lifetimes of VBi, VTe1 and VTe2 are 275 ps, 295 ps and 269 ps, respectively.

scholarly journals Bi2Te3 single crystals with high room-temperature thermoelectric performance enhanced by manipulating point defects based on first-principles calculation

RSC Advances ◽  
2019 ◽  
Vol 9 (25) ◽  
pp. 14422-14431 ◽  
Author(s):  
Chunmei Tang ◽  
Zhicheng Huang ◽  
Jun Pei ◽  
Bo-Ping Zhang ◽  
Peng-Peng Shang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Single Crystals ◽  
Point Defects ◽  
First Principles ◽  
Density Functional ◽  
Formation Energy ◽  
Room Temperature ◽  
First Principles Calculation ◽  
Functional Theory

This study prepared Bi2Te3 single crystals and investigated the thermoelectric properties of Bi2Te3 based on the electronic structure and formation energy of point defects which are calculated by density functional theory.

scholarly journals Tuning the optoelectronic properties of hematite with rhodium doping for photoelectrochemical water splitting using density functional theory approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdur Rauf ◽  
Muhammad Adil ◽  
Shabeer Ahmad Mian ◽  
Gul Rahman ◽  
Ejaz Ahmed ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Optical Absorption ◽  
Water Splitting ◽  
Density Functional ◽  
Formation Energy ◽  
Visible Region ◽  
Photoelectrochemical Water Splitting ◽  
Theory Approach ◽  
Functional Theory

AbstractHematite (Fe2O3) is one of the best candidates for photoelectrochemical water splitting due to its abundance and suitable bandgap. However, its efficiency is mostly impeded due to the intrinsically low conductivity and poor light absorption. In this study, we targeted this intrinsic behavior to investigate the thermodynamic stability, photoconductivity and optical properties of rhodium doped hematite using density functional theory. The calculated formation energy of pristine and rhodium doped hematite was − 4.47 eV and − 5.34 eV respectively, suggesting that the doped material is thermodynamically more stable. The DFT results established that the bandgap of doped hematite narrowed down to the lower edge (1.61 eV) in the visible region which enhanced the optical absorption and photoconductivity of the material. Moreover, doped hematite has the ability to absorb a broad spectrum (250–800) nm. The enhanced optical absorption boosted the photocurrent and incident photon to current efficiency. The calculated results also showed that the incorporation of rhodium in hematite induced a redshift in optical properties.

Vacancy formation energy in K2O

2018 ◽  
Author(s):  
V. P. Saleel Ahammad Saleel ◽  
R. D. Eithiraj
Keyword(s):  
Formation Energy ◽  
Vacancy Formation Energy ◽  
Vacancy Formation

Vacancy Formation Energy and Kinetic Properties of Liquid Metals

2021 ◽  
Vol 880 ◽  
pp. 43-48
Author(s):  
Yuri N. Starodubtsev ◽  
V.S. Tsepelev
Keyword(s):  
Diffusion Coefficient ◽  
Kinematic Viscosity ◽  
Formation Energy ◽  
Liquid Metals ◽  
Linear Regression Analysis ◽  
Vacancy Formation Energy ◽  
Vacancy Formation ◽  
Kinetic Properties ◽  
Self Diffusion ◽  
Self Diffusion Coefficient

We investigated the relationship of the vacancy formation energy with kinematic viscosity and self-diffusion coefficient in liquid metals at the melting temperature. Formulas are obtained that relate experimental values of the vacancy formation energy, kinematic viscosity, and self-diffusion coefficient to the atomic size and mass, the melting and Debye temperatures. The viscosity and self-diffusion parameters are introduced. The ratio of these parameters to vacancy formation energy is equal to dimensionless constants. It is shown that the formulas for viscosity and self-diffusion differ only in dimensionless constants; the values of these constants are calculated. Linear regression analysis was carried out and formulas with the highest adjusted coefficient of determination were identified. The calculated values of the self-diffusion coefficient for a large number of liquid metals are presented.

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