Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

Functional Theory ◽

Thin films of boron nitride (BN), particularly the sp2-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp2-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

10.26434/chemrxiv.8052218 ◽

2019 ◽

Author(s):

Henrik Pedersen ◽

Björn Alling ◽

Hans Högberg ◽

Annop Ektarawong

Keyword(s):

Thin Films ◽

Thermodynamic Stability ◽

First Principles ◽

Thermal Equilibrium ◽

Density Functional ◽

Van Der Waals ◽

Chemical Vapor ◽

Functional Theory ◽

Thin films of boron nitride (BN), particularly the sp2-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp2-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

10.26434/chemrxiv.8052218.v1 ◽

2019 ◽

Author(s):

Henrik Pedersen ◽

Björn Alling ◽

Hans Högberg ◽

Annop Ektarawong

Keyword(s):

Thin Films ◽

Thermodynamic Stability ◽

First Principles ◽

Thermal Equilibrium ◽

Density Functional ◽

Van Der Waals ◽

Chemical Vapor ◽

Functional Theory ◽

Thin films of boron nitride (BN), particularly the sp2-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp2-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Co-adsorption of O2 and H2O on Al(111) surface: a vdW-DFT study

RSC Advances ◽

10.1039/c6ra17054d ◽

2016 ◽

Vol 6 (83) ◽

pp. 79836-79843 ◽

Cited By ~ 1

Author(s):

Xin Wei ◽

Chaofang Dong ◽

Zhanghua Chen ◽

Kui Xiao ◽

Xiaogang Li

Keyword(s):

Density Functional Theory ◽

First Principles ◽

Density Functional ◽

Van Der Waals ◽

Co Adsorption ◽

Adsorption Behavior ◽

Dft Study ◽

Functional Theory

Using first-principles calculations based on van der Waals density functional theory, we systematically studied the co-adsorption behavior of H2O and O2 on Al(111) surfaces.

2018 15th International Conference on Electrical Engineering, Computing Science and Automatic Control (CCE) ◽

12 Possible Orientations of organic Formamidinium cation and its structural analysis by First Principles calculations using Van der Waals-Density functional Theory

10.1109/iceee.2018.8533994 ◽

2018 ◽

Cited By ~ 1

Author(s):

S. Karthick ◽

J. J. Rios-Ramirez ◽

S. Velumani

Keyword(s):

Density Functional Theory ◽

Structural Analysis ◽

First Principles ◽

Density Functional ◽

Van Der Waals ◽

Functional Theory

Thermodynamic stability of hexagonal and rhombohedral boron nitride under chemical vapor deposition conditions from van der Waals corrected first principles calculations

Journal of Vacuum Science & Technology A Vacuum Surfaces and Films ◽

10.1116/1.5107455 ◽

2019 ◽

Vol 37 (4) ◽

pp. 040603 ◽

Cited By ~ 4

Author(s):

Henrik Pedersen ◽

Björn Alling ◽

Hans Högberg ◽

Annop Ektarawong

Keyword(s):

Chemical Vapor Deposition ◽

Boron Nitride ◽

Thermodynamic Stability ◽

Vapor Deposition ◽

First Principles ◽

Van Der Waals ◽

Chemical Vapor ◽

Rhombohedral Boron ◽

Deposition Conditions

Thermodynamic Stability, Thermoelectric, Elastic and Electronic Structure Properties of ScMN2-Type (M = V, Nb, Ta) Phases Studied by ab initio Calculations

Condensed Matter ◽

10.3390/condmat4020036 ◽

2019 ◽

Vol 4 (2) ◽

pp. 36 ◽

Cited By ~ 1

Author(s):

Robert Pilemalm ◽

Leonid Pourovskii ◽

Igor Mosyagin ◽

Sergei Simak ◽

Per Eklund

Keyword(s):

Thermoelectric Properties ◽

Thermodynamic Stability ◽

First Principles ◽

Density Functional ◽

Mixing Enthalpy ◽

Electronic Density ◽

Functional Theory ◽

Small Band ◽

Structure Properties

ScMN2-type (M = V, Nb, Ta) phases are layered materials that have been experimentally reported for M = Ta and Nb, but they have up to now not been much studied. However, based on the properties of binary ScN and its alloys, it is reasonable to expect these phases to be of relevance in a range of applications, including thermoelectrics. Here, we have used first-principles calculations to study their thermodynamic stability, elastic, thermoelectric and electronic properties. We have used density functional theory to calculate lattice parameters, the mixing enthalpy of formation and electronic density of states as well as the thermoelectric properties and elastic constants (cij), bulk (B), shear (G) and Young’s (E) modulus, which were compared with available experimental data. Our results indicate that the considered systems are thermodynamically and elastically stable and that all are semiconductors with small band gaps. All three materials display anisotropic thermoelectric properties and indicate the possibility to tune these properties by doping. In particular, ScVN2, featuring the largest band gap exhibits a particularly large and strongly doping-sensitive Seebeck coefficient.

Stability, Elastic and Electronic Properties of Ta2N by First-Principles Calculations

Crystals ◽

10.3390/cryst11040445 ◽

2021 ◽

Vol 11 (4) ◽

pp. 445

Author(s):

Longpeng Zhu ◽

Jiong Wang ◽

Chenchen Dong ◽

Yong Du ◽

Shun-Li Shang ◽

...

Keyword(s):

Electronic Properties ◽

First Principles ◽

Density Functional ◽

Partial Density ◽

Functional Theory ◽

Charge Density Difference ◽

Resistance To Deformation ◽

The Stability ◽

The Enthalpy Of Formation

Owing to exploring the influence of the N atoms ordering in Ta2N compounds on their properties, the stability, elastic, and electronic properties of Ta2N compounds (Ta2N-I: P3¯ml and Ta2N-II: P3¯1m) were investigated using first-principles calculations based on density functional theory. Ta2N-II is energetically favorable according to the enthalpy of formation. Elastic constants were employed to reveal the stronger resistance to deformation, but weaker anisotropy, in Ta2N-II. A ductile-brittle transition was found between Ta2N-I (ductile) and Ta2N-II (brittle). The partial density of states showed a stronger orbital hybridization of Ta-d and N-p in Ta2N-II, resulting in stronger covalent bonding. The charge density difference illustrated the interaction of the Ta-N bond and electron distribution of Ta2N.

A DFT study of the adsorption of short peptides on Mg and Mg-based alloy surfaces

Physical Chemistry Chemical Physics ◽

10.1039/c7cp07431j ◽

2018 ◽

Vol 20 (5) ◽

pp. 3602-3607 ◽

Cited By ~ 9

Author(s):

Zhe Fang ◽

Jianfeng Wang ◽

Shijie Zhu ◽

Xiaofan Yang ◽

Yu Jia ◽

...

Keyword(s):

Density Functional Theory ◽

First Principles ◽

Density Functional ◽

Van Der Waals ◽

Mg Alloys ◽

Dft Study ◽

Short Peptides ◽

Functional Theory ◽

P Adsorption

Adsorption of short peptides, including three dipeptides: Arg–Gly, Gly–Asp, Arg–Asp, and one tripeptide RGD, on the surfaces of Mg and Mg alloys (Mg–Zn, Mg–Y, and Mg–Nd), was studied using first-principles calculations based on density functional theory (DFT), considering van der Waals (vdW) correction.

A Density Functional Theory Study of New Boron Nanotubes

Zeitschrift für Naturforschung A ◽

10.1515/zna-2017-0192 ◽

2017 ◽

Vol 72 (12) ◽

pp. 1145-1150

Author(s):

Zhao-Hua Chen ◽

Zun Xie

Keyword(s):

First Principles ◽

Density Functional ◽

Lithium Ion ◽

High Carrier Concentration ◽

Functional Theory ◽

Calculated Density ◽

High Carrier ◽

Deformation Electron Density ◽

AbstractUsing first-principles calculations, a series of new boron nanotubes (BNTs), which show various electronic properties, were theoretically predicted. Stable nanotubes with various chiral vectors and diameters can be formed by rolling up the boron sheet with relative stability [H. Tang and S. I. Beigi, Phys. Rev. B 82, 115412 (2010).]. By increasing the diameter for BNT, the stability is enhanced. The calculated density of states and band structures demonstrate that all the predicted BNTs are metallic, regardless of their diameter and chirality. The multicentre chemical bonds of the relatively stable boron sheet and BNTs are analysed using the deformation electron density. Within our study, the BNTs all have metallic conductive characteristics, in addition to having a low effective quality and high carrier concentration, which are very good nanoconductive material properties and could be combined to form high-power electrodes for lithium-ion batteries such as those used in many modern electronics.