scholarly journals Stress and Strain Prediction of Zirconium Nitride under Oxygen Doping and Vacancy Introduction

2021 ◽  
Vol 6 (3) ◽  
pp. 32
Author(s):  
Junfei Cai ◽  
Sicheng Wu ◽  
Jinjin Li
Keyword(s):  
Mechanical Property ◽  
Tensile Strength ◽  
Density Functional ◽  
High Hardness ◽  
Zirconium Nitride ◽  
Oxygen Doping ◽  
Functional Theory ◽  
Practical Applications ◽  
Properties Of Materials ◽  
Property Changes

Zirconium nitride (ZrN) is an important material for the mechanical industries due to its excellent properties such as excellent wear resistance, high hardness, etc. In practical applications, it is necessary to study how to regulate the mechanical properties of materials to meet the needs of different applications. To better understand the influence of vacancies and oxygen on the mechanical property of ZrN, we studied the tensile strength of the ZrN with oxygen atom doping and zirconium vacancy introduction by ab initio density functional theory. The mechanical property changes of modified ZrN in three crystallographic directions (<001>, <110>, and <111>) were calculated. The results show that the tensile strength of ZrN can be increased by oxygen doping at a certain concentration, while that of ZrN can be decreased by the introduction of zirconium vacancy.

A First-Principles Computational Comparison of the Aqueous Anatase TiO2 (001) Interface and the Disordered, Fluorinated TiO2 Interface

2018 ◽  
Author(s):  
Kyle Reeves ◽  
Damien Dambournet ◽  
Christel Laberty-Robert ◽  
Rodolphe Vuilleumier ◽  
Mathieu Salanne
Keyword(s):  
Density Of States ◽  
Density Functional ◽  
Water Dissociation ◽  
Water Molecules ◽  
Chemical Doping ◽  
Charge Balance ◽  
Functional Theory ◽  
Adsorption Of Water ◽  
Properties Of Materials ◽  
Computational Comparison

Chemical doping and other surface modifications have been used to engineer the bulk properties of materials, but their influence on the surface structure and consequently the surface chemistry are often unknown. Previous work has been successful in fluorinating anatase TiO<sub>2</sub> with charge balance achieved via the introduction of Ti vacancies rather than the reduction of Ti. Our work here investigates the interface between this fluorinated titanate with cationic vacancies and a<br>monolayer of water via density functional theory based molecular dynamics. We compute the projected density of states for only those atoms at the interface and for those states that fall within 1eV of the Fermi energy for various steps throughout the simulation, and we determine that the<br>variation in this representation of the density of states serves as a reasonable tool to anticipate where surfaces are most likely to be reactive. In particular, we conclude that water dissociation at the surface is the main mechanism that influences the anatase (001) surface whereas the change in<br>the density of states at the surface of the fluorinated structure is influenced primarily through the adsorption of water molecules at the surface.

A First-Principles Computational Comparison of the Aqueous Anatase TiO2 (001) Interface and the Disordered, Fluorinated TiO2 Interface

2018 ◽  
Author(s):  
Kyle Reeves ◽  
Damien Dambournet ◽  
Christel Laberty-Robert ◽  
Rodolphe Vuilleumier ◽  
Mathieu Salanne
Keyword(s):  
Density Of States ◽  
Density Functional ◽  
Water Dissociation ◽  
Water Molecules ◽  
Chemical Doping ◽  
Charge Balance ◽  
Functional Theory ◽  
Adsorption Of Water ◽  
Properties Of Materials ◽  
Computational Comparison

Chemical doping and other surface modifications have been used to engineer the bulk properties of materials, but their influence on the surface structure and consequently the surface chemistry are often unknown. Previous work has been successful in fluorinating anatase TiO<sub>2</sub> with charge balance achieved via the introduction of Ti vacancies rather than the reduction of Ti. Our work here investigates the interface between this fluorinated titanate with cationic vacancies and a<br>monolayer of water via density functional theory based molecular dynamics. We compute the projected density of states for only those atoms at the interface and for those states that fall within 1eV of the Fermi energy for various steps throughout the simulation, and we determine that the<br>variation in this representation of the density of states serves as a reasonable tool to anticipate where surfaces are most likely to be reactive. In particular, we conclude that water dissociation at the surface is the main mechanism that influences the anatase (001) surface whereas the change in<br>the density of states at the surface of the fluorinated structure is influenced primarily through the adsorption of water molecules at the surface.

Understanding the ML black box with simple descriptors to predict cluster–adsorbate interaction energy

2020 ◽  
Vol 44 (20) ◽  
pp. 8545-8553
Author(s):  
Sheena Agarwal ◽  
Shweta Mehta ◽  
Kavita Joshi
Keyword(s):  
Density Functional Theory ◽  
Interaction Energy ◽  
Density Functional ◽  
Black Box ◽  
Functional Theory ◽  
Properties Of Materials ◽  
Insight Into

Density functional theory (DFT) is currently one of the most accurate and yet practical theories used to gain insight into the properties of materials.

Influences of Fe Doping on the Electronic Structure of Mg(0001) Surface and Hydrogenation Mechanism in Fe-Doped Mg(0001) Surface

2013 ◽  
Vol 873 ◽  
pp. 114-120 ◽  
Author(s):  
Zhi Wen Wang ◽  
Xin Jun Guo ◽  
Hong Xia Zhang ◽  
Li Li
Keyword(s):  
Density Functional ◽  
Hydrogen Molecule ◽  
Functional Theory ◽  
Practical Applications ◽  
Atom Diffusion ◽  
Charge Density Difference ◽  
The Density Functional Theory ◽  
Diffusion Paths ◽  
The Stability ◽  
Dissociation Path

First-principles calculations within the density functional theory (DFT) have been carried out to study the interaction of hydrogen molecule with Fe-doped Mg (0001) surfaces. First we have calculated the stability of the Fe atom on the Mg surface, On the basis of the energetic criteria, Fe atom prefer to substitute one of the Mg atoms from the second layer. In the second step, we have studied the interaction between hydrogen molecule and the Fe-doped Mg (0001) surface. The results show that for Fe atoms doped Mg (0001) surface in the second layer, enhances the chemisorption interaction between H2molecule and Fe atom, but also benefits H atom diffusion into Mg bulk with relatively more diffusion paths compared with that of clean Mg surface. Charge density difference plots provided some ideas about why certain alloying elements on the surface reduce the energy barrier of H2molecule dissociation on Fe-doped Mg (0001) surface. We can see that Fe as catalyst for the hydrogenation/dehydrogenation of Mg alloy samples and provide more dissociation path for H2molecule and diffusion paths for H atom, The present results not only beneficial for clarify the experimentally observed fast hydrogenation kinetics for Fe-capped Mg materials but also help to design new types of hydrogen storage materials for practical applications in the auto industry.

scholarly journals Ab Initio Study of Elastic and Mechanical Properties in FeCrMn Alloys

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1129 ◽  
Author(s):  
Vsevolod Razumovskiy ◽  
Carola Hahn ◽  
Marina Lukas ◽  
Lorenz Romaner
Keyword(s):  
Mechanical Properties ◽  
Density Functional ◽  
Magnetic State ◽  
Stacking Fault ◽  
Functional Theory ◽  
Temperature Changes ◽  
Practical Applications ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Stacking Fault Energies

Mechanical properties of FeCrMn-based steels are of major importance for practical applications. In this work, we investigate mechanical properties of disordered paramagnetic fcc FeCr 10 – 16 Mn 12 – 32 alloys using density functional theory. The effects of composition and temperature changes on the magnetic state, elastic properties and stacking fault energies of the alloys are studied. Calculated dependencies of the lattice and elastic constants are used to evaluate the effect of the solid solution strengthening by Mn and Cr using a modified Labusch-Nabarro model and a model for concentrated alloys. The effect of Cr and Mn alloying on the stacking fault energies is calculated and discussed in connection to possible deformation mechanisms.

Regulation of Electrical Properties of ZrOxNy by Oxygen Doping and Zirconium Vacancies

2021 ◽  
Author(s):  
Junfei Cai，Sicheng Wu ◽  
Jinjin Li
Keyword(s):  
Electrical Properties ◽  
Transition Metal ◽  
Density Functional ◽  
Electronic Devices ◽  
High Sensitivity ◽  
High Electron ◽  
Oxygen Doping ◽  
Functional Theory ◽  
Formation Energies ◽  
Semiconductor Properties

Transition metal oxynitrides are important materials in electronic devices, electrocatalysis, machinery industry and other fields, according to their excellent properties, such as high sensitivity to temperature and high electron transport characteristics. Especially in sensor and MOS applications, transition metal oxynitrides with semiconductor properties play an important role in the sensitivity and frequency response of sensors. Here, we study the effects of different concentrations of zirconium vacancy (VZr) and oxygen doping on the ZrN structure, and calculate the formation energies and density of states of ZrOxNy in different element ratios by density functional theory. The results show that the introduction of VZr and oxygen doping promote the Fermi level of ZrOxNy to move towards the valence band and conduction band, respectively. The structure of the non-degenerate semiconductor ZrOxNy can be constructed at Zr0.425N0.569O0.006. Taking ZrOxNy as an example, this work proposes a method to regulate the electrical properties of transition metal oxynitrides by introducing zirconium vacancy/oxygen doping, which greatly promotes the rapid discovery of novel transition metal oxynitrides semiconductor materials.

Structural and elastic properties of ZrN and HfN: ab initio study

2014 ◽  
Vol 92 (9) ◽  
pp. 1058-1061 ◽  
Author(s):  
Anurag Srivastava ◽  
Bhoopendra Dhar Diwan
Keyword(s):  
Elastic Properties ◽  
Density Functional ◽  
Zirconium Nitride ◽  
Energy Calculation ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Hafnium Nitride ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
The Stability

The present paper discusses the density functional theory based stability analysis of zirconium nitride and hafnium nitride in its rocksalt (B1), CsCl (B2), and zinc blende (B3) type phases. The ground state total energy calculation approach of the system has been used through the generalized gradient approximation parameterized with revised Perdew–Burke–Ernzerhof as exchange correlation functional. The present theoretical analysis confirms the stability trend of phases from most stable to less stable as B1 → B2 → B3. The study also reports the analysis of elastic properties of these nitrides in its most stable B1-type phase.

Study on Mechanical Property of Conch Powder Reinforced Polyethylene Composite

2012 ◽  
Vol 557-559 ◽  
pp. 286-290
Author(s):  
Zhi Hong Guo ◽  
Jia Wei Shi ◽  
Qun Shao ◽  
Pei Jie Lin ◽  
Yan Ping Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
High Tensile Strength ◽  
Frictional Loss ◽  
Practical Applications ◽  
Impact Performance ◽  
Polyethylene Composite ◽  
Maximum Value ◽  
The Impact

The impact performance of PE can be greatly enhanced by the use of functionalized conch powder, while maintaining high tensile strength thus giving this study high potentiality for its practical applications. The conch powder was treated by titanate coupling agent NDZ-201 before use and the influence of different proportions of conch powder on the mechanical properties of PE/conch powder composite is discussed in this article. The impact strength has a maximum value of 63.4kJ/m2 and the frictional loss records a minimum of 4.27×10-1mm3/(Nm)-1 and 42.2% lower than that of pure PE.

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