Influence of Sn/Ge Cation Exchange on Vacancy-Ordered Double Perovskite Cs2 Sn(1−x ) Ge x I6 : A First-Principles Theoretical Study

2018 ◽  
Vol 256 (3) ◽  
pp. 1800427 ◽  
Author(s):  
Xia-Xia Ma ◽  
Ze-Sheng Li
Keyword(s):  
Cation Exchange ◽  
First Principles ◽  
Theoretical Study ◽  
Double Perovskite

First-principles investigations of Ba2NaIO6 double Perovskite semiconductor: Material for low-cost energy technologies

2022 ◽  
Vol 275 ◽  
pp. 125237
Author(s):  
Samah Al-Qaisi ◽  
Malak Azmat Ali ◽  
Tahani A. Alrebdi ◽  
Tuan V. Vu ◽  
Manal Morsi ◽  
...  
Keyword(s):  
First Principles ◽  
Low Cost ◽  
Double Perovskite ◽  
Semiconductor Material ◽  
Energy Technologies

scholarly journals Strain Conditions for the Inverse Heusler Type Fully Compensated Spin-Gapless Semiconductor Ti2MnAl: A First-Principles Study

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2091 ◽  
Author(s):  
Tie Yang ◽  
Liyu Hao ◽  
Rabah Khenata ◽  
Xiaotian Wang
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Density Functional ◽  
Theoretical Study ◽  
Debye Model ◽  
Pressure Effects ◽  
First Principles Calculation ◽  
Strain Condition ◽  
Functional Theory ◽  
Future Work

In this work, we systematically studied the structural, electronic, magnetic, mechanical and thermodynamic properties of the fully compensated spin-gapless inverse Heusler Ti2MnAl compound under pressure strain condition by applying the first-principles calculation based on density functional theory and the quasi-harmonic Debye model. The obtained structural, electronic and magnetic behaviors without pressure are well consistent with previous studies. It is found that the spin-gapless characteristic is destroyed at 20 GPa and then restored with further increase in pressure. While, the fully compensated ferromagnetism shows a better resistance against the pressure up to 30 GPa and then becomes to non-magnetism at higher pressure. Tetragonal distortion has also been investigated and it is found the spin-gapless property is only destroyed when c/a is less than 1 at 95% volume. Three independent elastic constants and various moduli have been calculated and they all show increasing tendency with pressure increase. Additionally, the pressure effects on the thermodynamic properties under different temperature have been studied, including the normalized volume, thermal expansion coefficient, heat capacity at constant volume, Grüneisen constant and Debye temperature. Overall, this theoretical study presents a detailed analysis of the physical properties’ variation under strain condition from different aspects on Ti2MnAl and, thus, can provide a helpful reference for the future work and even inspire some new studies and lead to some insight on the application of this material.

First Principles Theoretical Study of 4H-SiC/SiO2Interfacial Electronic States on (0001), (000\bar1), and (11\bar20)

2008 ◽  
Vol 1 ◽  
pp. 061401 ◽  
Author(s):  
Eiichi Okuno ◽  
Toshio Sakakibara ◽  
Shoichi Onda ◽  
Makoto Itoh ◽  
Tsuyoshi Uda
Keyword(s):  
First Principles ◽  
Theoretical Study ◽  
Electronic States

FIRST PRINCIPLES DENSITY FUNCTIONAL INVESTIGATION OF SUPPORTED TUNGSTEN CLUSTER (Wn; n = 1 TO 6) ON ANCHORED GRAPHITE (0001) SURFACE

2013 ◽  
Vol 02 (03n04) ◽  
pp. 1350015
Author(s):  
SONALI BARMAN ◽  
G. P. DAS ◽  
Y. KAWAZOE
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Metal Clusters ◽  
Theoretical Study ◽  
First Principles Calculations ◽  
Novel Technique ◽  
Defect Site ◽  
Positive Ions ◽  
Spin Polarized ◽  
Functional Investigation

Size-selected Wn clusters can be deposited firmly on a graphite (0001) surface using a novel technique, where the positive ions (of the same metal atom species) embedded on the graphite surface by ion implantation, act as anchors. The size selected metal clusters can then soft land on this anchored surface m [Hayakawa et al., 2009]. We have carried out a systematic theoretical study of the adsorption of Wn (n = 1-6) clusters on anchored graphite (0001) surface, using state-of-art spin-polarized density functional approach. In our first-principles calculations, the graphite (0001) surface has been suitably modeled as a slab separated by large vacuum layers. Wn clusters bond on clean graphite (0001) surface with a rather weak Van-der-Waals interaction. However, on the anchored graphite (0001) surface, the Wn clusters get absorbed at the defect site with a much larger adsorption energy. We report here the results of our first-principles investigation of this supported Wn cluster system, along with their reactivity trend as a function of the cluster size (n).

scholarly journals A theoretical study of blue phosphorene nanoribbons based on first-principles calculations

2014 ◽  
Vol 116 (7) ◽  
pp. 073704 ◽  
Author(s):  
Jiafeng Xie ◽  
M. S. Si ◽  
D. Z. Yang ◽  
Z. Y. Zhang ◽  
D. S. Xue
Keyword(s):  
First Principles ◽  
Theoretical Study ◽  
First Principles Calculations ◽  
Blue Phosphorene

scholarly journals Theoretical Study on Proton Diffusivity in Y-Doped BaZrO3 with Realistic Dopant Configurations

2020 ◽  
Author(s):  
Takeo Fujii ◽  
Kazuaki Toyoura ◽  
Tetsuya Uda ◽  
Shusuke Kasamatsu
Keyword(s):  
First Principles ◽  
Theoretical Study ◽  
Site Effect ◽  
Barium Zirconate ◽  
Proton Proton ◽  
Potential Wells ◽  
Proton Interaction ◽  
Master Equation Approach ◽  
Replica Exchange Monte Carlo ◽  
Random Configuration

We theoretically revisit the proton diffusivity in yttrium-doped barium zirconate (Y-doped BaZrO<sub>3</sub>) with realistic dopant configurations under processing conditions. In a recent study employing the replica exchange Monte Carlo method, the equilibrium Y configurations at typical sintering temperatures were shown to deviate from the random configuration assumed in earlier theoretical studies. In the present study, we took this observation into account and evaluated the effect of the Y configuration on the proton diffusivity. Using the master equation approach based on local diffusion barriers calculated from first principles, the proton diffusivities under realistic Y configurations were estimated to be higher than those in the random configuration. This is explained by the fact that realistic Y configurations have fewer trap sites with deep potential wells compared to the random configuration due to the isolation trend of Y dopants. In addition, the effects of proton-proton interaction and the abundance of preferential conduction pathways are discussed; it is found that both are relatively minor factors compared to the trap site effect in determining the dependence of the proton diffusivity on the Y configurations.<br>

scholarly journals First-Principles Calculations of High-Pressure Physical Properties of Ti0.5Ta0.5 Alloy

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 796
Author(s):  
Fang Yu ◽  
Yu Liu
Keyword(s):  
High Pressure ◽  
Physical Properties ◽  
First Principles ◽  
Theoretical Study ◽  
Applied Pressure ◽  
Lattice Parameter ◽  
Physical Parameters ◽  
First Principles Calculations ◽  
Analysis Method ◽  
Metallic Bond

In this paper, an in-depth theoretical study on some physical properties of Ti0.5Ta0.5 alloy with systematic symmetry under high pressure is conducted via first-principles calculations, and relevant physical parameters are calculated. The results demonstrate that the calculated parameters, including lattice parameter, elastic constants, and elastic moduli, fit well with available theoretical and experimental data when the Ti0.5Ta0.5 alloy is under T = 0 and P = 0 , indicating that the theoretical analysis method can effectively predict the physical properties of the Ti0.5Ta0.5 alloy. The microstructure and macroscopic physical properties of the alloy cannot be destroyed as the applied pressure ranges from 0 to 50GPa, but the phase transition of crystal structure may occur in the Ti0.5Ta0.5 alloy if the applied pressure continues to increase according to the TDOS curves and charge density diagram. The value of Young’s and shear modulus is maximized at P = 25   GPa . The anisotropy factors A ( 100 ) [ 001 ] and A ( 110 ) [ 001 ] are equal to 1, suggesting the Ti0.5Ta0.5 alloy is an isotropic material at 28 GPa, and the metallic bond is strengthened under high pressure. The present results provide helpful insights into the physical properties of Ti0.5Ta0.5 alloy.

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