scholarly journals Formation energies of intrinsic point defects in monoclinic VO2studied by first-principles calculations

AIP Advances ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 105301 ◽  
Author(s):  
Yuanyuan Cui ◽  
Bin Liu ◽  
Lanli Chen ◽  
Hongjie Luo ◽  
Yanfeng Gao
Keyword(s):  
Point Defects ◽  
First Principles ◽  
First Principles Calculations ◽  
Intrinsic Point Defects ◽  
Formation Energies

First Principles Study of Point Defects in Uranium Dioxide

2007 ◽  
Vol 561-565 ◽  
pp. 1971-1974 ◽  
Author(s):  
Ying Chen ◽  
Misako Iwasawa ◽  
Yasunori Kaneta ◽  
Toshiharu Ohnuma ◽  
Hua Yun Geng ◽  
...  
Keyword(s):  
Point Defects ◽  
First Principles ◽  
Defect Formation ◽  
Lattice Relaxation ◽  
Atomic Displacement ◽  
Grain Structure ◽  
First Principles Calculations ◽  
Fine Grain ◽  
Unit Cells ◽  
Formation Energies

To clarify the origin of a characteristic fine grain structure formed under the high burn-up of the nuclear fuel, the comprehensive first-principles calculations for UO2 containing various types of point defect have been performed by the PAW-GGA+U with lattice relaxation for supercells containing 1, 2 and 8 unit cells of UO2. The electronic structure, the atomic displacement and the defect formation energies of defective systems are obtained, and the effects of supercell size on these properties are discussed. Based on this relatively high precise self-consistent formation energies dataset, thermodynamic properties of various types of point defects in UO2 are further investigated in the framework of the point defects model.

Theoretical investigation of thermodynamic stability and mobility of the intrinsic point defects in Ti3AC2 (A = Si, Al)

2015 ◽  
Vol 17 (14) ◽  
pp. 8927-8934 ◽  
Author(s):  
Jiemin Wang ◽  
Bin Liu ◽  
Jingyang Wang ◽  
Yanchun Zhou
Keyword(s):  
Theoretical Investigation ◽  
Point Defects ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Intrinsic Point Defects ◽  
And Migration ◽  
Formation Energies ◽  
First Principles Method

Interstitial configurations, formation energies, and migration paths of intrinsic point defects of Ti3AC2 (A = Si or Al) were investigated by a first-principles method.

Intrinsic point defects in buckled and puckered arsenene: a first-principles study

2017 ◽  
Vol 19 (15) ◽  
pp. 9862-9871 ◽  
Author(s):  
K. Iordanidou ◽  
J. Kioseoglou ◽  
V. V. Afanas’ev ◽  
A. Stesmans ◽  
M. Houssa
Keyword(s):  
Electronic Properties ◽  
Point Defects ◽  
First Principles ◽  
First Principles Calculations ◽  
Intrinsic Point Defects ◽  
First Principles Study ◽  
The Impact

Using first-principles calculations, we study the impact of various point defects on the structural, energetic, and electronic properties of arsenene.

scholarly journals First Principles Calculations of Defects in Unstable Crystals: Austenitic Iron

2011 ◽  
Vol 1363 ◽  
Author(s):  
G.J. Ackland ◽  
T.P.C. Klaver ◽  
D.J. Hepburn
Keyword(s):  
Point Defects ◽  
First Principles ◽  
Defect Formation ◽  
Single Layer ◽  
Temperature Limit ◽  
Reference State ◽  
First Principles Calculations ◽  
General Picture ◽  
Bcc Iron ◽  
Defect Energies

ABSTRACTFirst principles calculations have given a new insight into the energies of point defects in many different materials, information which cannot be readily obtained from experiment. Most such calculations are done at zero Kelvin, with the assumption that finite temperature effects on defect energies and barriers are small. In some materials, however, the stable crystal structure of interest is mechanically unstable at 0K. In such cases, alternate approaches are needed. Here we present results of first principles calculations of austenitic iron using the VASP code. We determine an appropriate reference state for collinear magnetism to be the antiferromagnetic (001) double-layer (AFM-d) which is both stable and lower in energy than other possible models for the low temperature limit of paramagnetic fcc iron. Another plausible reference state is the antiferromagnetic (001) single layer (AFM-1). We then consider the energetics of dissolving typical alloying impurities (Ni, Cr) in the materials, and their interaction with point defects typical of the irradiated environment. We show that the calculated defect formation energies have fairly high dependence on the reference state chosen: in some cases this is due to instability of the reference state, a problem which does not seem to apply to AFM-d and AFM-1. Furthermore, there is a correlation between local free volume magnetism and energetics. Despite this, a general picture emerge that point defects in austenitic iron have geometries similar to those in simpler, non-magnetic, thermodynamically stable FCC metals. The defect energies are similar to those in BCC iron. The effect of substitutional Ni and Cr on defect properties is weak, rarely more than tenths of eV, so it is unlikely that small amounts of Ni and Cr will have a significant effect on the radiation damage in austenitic iron at high temperatures.

Stability and Structures of Constitutional Defects in Nonstoichiometric Intermetallic Compounds by First-Principles Calculations

2005 ◽  
Vol 475-479 ◽  
pp. 3111-3114
Author(s):  
Masataka Mizuno ◽  
Hideki Araki ◽  
Yasuharu Shirai
Keyword(s):  
Intermetallic Compounds ◽  
First Principles ◽  
Electronic Structures ◽  
Stoichiometric Composition ◽  
Electronic Structure Calculations ◽  
First Principles Calculations ◽  
Compositional Dependence ◽  
Wide Range ◽  
Formation Energies ◽  
Structure Calculations

Some of intermetallic compounds exist in a wide range of concentration around the stoichiometric composition. First-principles electronic structure calculations have been performed for constitutional defects in non-stoichiometric CoAl and CoTi in order to investigate their stabilities and structural relaxations induced by constitutional defects. For the evaluation of stabilities of constitutional defects, the compositional dependence curves both of formation energies and of lattice parameters are obtained by the calculations employing supercells in various sizes. The lattice relaxations around constitutional defects are discussed by analyzing the change in electronic structures induced by constitutional defects.

scholarly journals Effect of point defects on the electronic density states of SnC nanosheets: First-principles calculations

2017 ◽  
Vol 7 ◽  
pp. 3209-3215 ◽  
Author(s):  
Soleyman Majidi ◽  
Amine Achour ◽  
D.P. Rai ◽  
Payman Nayebi ◽  
Shahram Solaymani ◽  
...  
Keyword(s):  
Point Defects ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic Density
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