First principle calculations of MAX ceramics Cr2GeC, V2GeC and their substitutional solid solutions

The band structure and density of states (DOS) of Ti1-xSnxO2 solid solutions with x=0, 1/8, 1/4, 1/2 and 1 were investigated by means of the first-principle calculations based on density functional theory. The result indicated that band gap and Fermi level of TiO2-SnO2 vary continuously from those of pure TiO2 to those of Sn content increasing. In addition, the DOS moves towards low energy and the bang gap is broadened with growing value of x. The wide band gap and the low density of the states in the conduction band result in the enhancement of photoactivity in Ti1-xSnxO2.

Solid Solutions of AB2C4 Defect Semiconductors

MRS Proceedings ◽

10.1557/proc-141-195 ◽

1988 ◽

Vol 141 ◽

Cited By ~ 1

Author(s):

T.M. de Pascale ◽

M. Marinelli ◽

F. Meloni ◽

G. Mula ◽

M. Serra ◽

...

Keyword(s):

Total Energy ◽

Structural Stability ◽

Solid Solutions ◽

Spinel Structure ◽

Theoretical Study ◽

Stability Diagram ◽

First Principle ◽

Crystalline Phases ◽

AbstractAB2C4 defect semiconductors can be thought of as generalized zincblende compounds, in which the presence of two different cations and of vacant sites favours the formation of several crystalline phases. In this work we present a theoretical study of the structural stability of the ZnxCdl-xIn2S4 solid solutions. The end compounds crystallize in a layer (x = 1) and in a spinel structure (x = 0). Total energy first principle calculations have been performed for both phases and for various values of x. The theoretical structural stability diagram compares very well with experiment.

Phonon Spectrum of Crystals InxTl1 – xI Substitutional Solid Solutions

Journal of Nano- and Electronic Physics ◽

10.21272/jnep.8(1).01010 ◽

2016 ◽

Vol 8 (1) ◽

pp. 01010-1-01010-5 ◽

Cited By ~ 5

Author(s):

A. I. Kashuba ◽

◽

S. V. Apunevych ◽

Keyword(s):

Solid Solutions ◽

Phonon Spectrum ◽

Substitutional Solid Solutions

High-temperature oxidation behavior of CVD-SiC ceramic coating in wet oxygen and structural evolution of oxidation product: Experiment and first-principle calculations

Applied Surface Science ◽

10.1016/j.apsusc.2021.149808 ◽

2021 ◽

Vol 556 ◽

pp. 149808

Author(s):

Pengfei Zhang ◽

Yulei Zhang ◽

Guohui Chen ◽

Wenhan Gai ◽

Jingan Kong

Keyword(s):

High Temperature ◽

High Temperature Oxidation ◽

Oxidation Behavior ◽

Ceramic Coating ◽

Structural Evolution ◽

First Principle ◽

Temperature Oxidation ◽

High Temperature Oxidation Behavior

Sic Ceramic ◽

A First-Principle Study of Monolayer Transition Metal Carbon Trichalcogenides

Journal of Superconductivity and Novel Magnetism ◽

10.1007/s10948-021-05980-1 ◽

2021 ◽

Author(s):

Muhammad Yar Khan ◽

Yan Liu ◽

Tao Wang ◽

Hu Long ◽

Miaogen Chen ◽

...

Keyword(s):

Phonon Dispersion ◽

Magnetic Ordering ◽

Dimensional Structure ◽

First Principle ◽

Two Dimensional ◽

Biaxial Strain ◽

Half Metallic ◽

Potential Applications ◽

External Strain

AbstractMonolayer MnCX3 metal–carbon trichalcogenides have been investigated by using the first-principle calculations. The compounds show half-metallic ferromagnetic characters. Our results reveal that their electronic and magnetic properties can be altered by applying uniaxial or biaxial strain. By tuning the strength of the external strain, the electronic bandgap and magnetic ordering of the compounds change and result in a phase transition from the half-metallic to the semiconducting phase. Furthermore, the vibrational and thermodynamic stability of the two-dimensional structure has been verified by calculating the phonon dispersion and molecular dynamics. Our study paves guidance for the potential applications of these two mono-layers in the future for spintronics and straintronics devices.

Monolayer 1T and 1T′ MoSO as Promising Electrocatalyst for Hydrogen Evolution based on First Principle Calculations

ChemPhysChem ◽

10.1002/cphc.202100038 ◽

2021 ◽

Author(s):

Feifei Li ◽

Ziping Niu ◽

Lixin Zhang

Keyword(s):

Hydrogen Evolution ◽

First Principle ◽

Quantitative Evaluations of Hydrogen Diffusivity in V-X (X = Cr, Al, Pd) Alloy Membranes Based on Hydrogen Chemical Potential

Membranes ◽

10.3390/membranes11010067 ◽

2021 ◽

Vol 11 (1) ◽

pp. 67

Author(s):

Asuka Suzuki ◽

Hiroshi Yukawa

Keyword(s):

Nearest Neighbor ◽

Chemical Potential ◽

Hydrogen Permeability ◽

First Principle ◽

Hydrogen Diffusivity ◽

Hydrogen Atoms ◽

Blocking Effects ◽

Pd Alloy ◽

Quantitative Evaluations

Vanadium (V) has higher hydrogen permeability than Pd-based alloy membranes but exhibits poor resistance to hydrogen-induced embrittlement. The alloy elements are added to reduce hydrogen solubility and prevent hydrogen-induced embrittlement. To enhance hydrogen permeability, the alloy elements which improve hydrogen diffusivity in V are more suitable. In the present study, hydrogen diffusivity in V-Cr, V-Al, and V-Pd alloy membranes was investigated in view of the hydrogen chemical potential and compared with the previously reported results of V-Fe alloy membranes. The additions of Cr and Fe to V improved the mobility of hydrogen atoms. In contrast, those of Al and Pd decreased hydrogen diffusivity. The first principle calculations revealed that the hydrogen atoms cannot occupy the first-nearest neighbor T sites (T1 sites) of Al and Pd in the V crystal lattice. These blocking effects will be a dominant contributor to decreasing hydrogen diffusivity by the additions of Al and Pd. For V-based alloy membranes, Fe and Cr are more suitable alloy elements compared with Al and Pd in view of hydrogen diffusivity.

Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

Scientific Reports ◽

10.1038/s41598-020-78598-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Durga Sankar Vavilapalli ◽

Ambrose A. Melvin ◽

F. Bellarmine ◽

Ramanjaneyulu Mannam ◽

Srihari Velaga ◽

...

Keyword(s):

Single Crystal ◽

Single Crystals ◽

Photoelectron Spectroscopy ◽

Diffraction Method ◽

Lattice Parameter ◽

First Principle ◽

X Ray Diffraction ◽

X Ray ◽

Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

Author Correction: Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

Scientific Reports ◽

10.1038/s41598-021-85663-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Durga Sankar Vavilapalli ◽

Ambrose A. Melvin ◽

F. Bellarmine ◽

Ramanjaneyulu Mannam ◽

Srihari Velaga ◽

...

Keyword(s):

Single Crystals ◽

First Principle ◽

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The thermal stability of FAPbBr3 nanocrystals from temperature-dependent photoluminescence and first-principles calculations

RSC Advances ◽

10.1039/d0ra07668f ◽

2020 ◽

Vol 10 (72) ◽

pp. 44373-44381

Author(s):

Xiaozhe Wang ◽

Qi Wang ◽

Zhijun Chai ◽

Wenzhi Wu

Keyword(s):

First Principles ◽

First Principle ◽

First Principles Calculations ◽

Temperature Dependent ◽

Time Resolved ◽

Temperature Dependent Photoluminescence

Steady State Time ◽

Time Resolved Photoluminescence ◽

Thermal Stability Of ◽

The thermal properties of FAPbBr3 perovskite nanocrystals (PNCs) is investigated by use of temperature-dependent steady-state/time-resolved photoluminescence and first-principle calculations.