Shear-strain gradient induced polarization reversal in ferroelectric BaTiO3 thin films: A first-principles total-energy study

2017 ◽  
Vol 95 (14) ◽  
Author(s):  
Guannan Li ◽  
Xiaokun Huang ◽  
Jingsan Hu ◽  
Weiyi Zhang
Keyword(s):  
Thin Films ◽  
Total Energy ◽  
Shear Strain ◽  
Strain Gradient ◽  
First Principles ◽  
Induced Polarization ◽  
Polarization Reversal

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

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 ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-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 sp<sup>2</sup>-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.

Site preference and atomic ordering in the ternary Rh5Ga2As: first-principles calculations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nilanjan Roy ◽  
Sucharita Giri ◽  
Harshit ◽  
Partha P. Jana
Keyword(s):  
Total Energy ◽  
First Principles ◽  
Density Functional ◽  
Structure Type ◽  
Site Preference ◽  
X Ray Diffraction ◽  
Atomic Ordering ◽  
Functional Theory ◽  
The Stability ◽  
Bonding Characteristics

Abstract The site preference and atomic ordering of the ternary Rh5Ga2As have been investigated using first-principles density functional theory (DFT). An interesting atomic ordering of two neighboring elements Ga and As reported in the structure of Rh5Ga2As by X-ray diffraction data only is confirmed by first-principles total-energy calculations. The previously reported experimental model with Ga/As ordering is indeed the most stable in the structure of Rh5Ga2As. The calculation detected that there is an obvious trend concerning the influence of the heteroatomic Rh–Ga/As contacts on the calculated total energy. Interestingly, the orderly distribution of As and Ga that is found in the binary GaAs (Zinc-blende structure type), retained to ternary Rh5Ga2As. The density of states (DOS) and Crystal Orbital Hamiltonian Population (COHP) are calculated to enlighten the stability and bonding characteristics in the structure of Rh5Ga2As. The bonding analysis also confirms that Rh–Ga/As short contacts are the major driving force towards the overall stability of the compound.

Interface coupling and charge doping in graphene on ferroelectric BiAlO3(0001) polar surfaces

2021 ◽  
Vol 23 (5) ◽  
pp. 3407-3416
Author(s):  
Jin Yuan ◽  
Jian-Qing Dai ◽  
Cheng Ke ◽  
Zi-Cheng Wei
Keyword(s):  
Dft Calculations ◽  
Hybrid System ◽  
First Principles ◽  
Doping Effect ◽  
Coupling Mechanism ◽  
Polarization Reversal ◽  
Interface Coupling ◽  
Polar Surfaces ◽  
Charge Doping

The interface coupling mechanism, charge doping effect, and effect of polarization reversal in the graphene/BiAlO3(0001) hybrid system are explored by first-principles DFT calculations.

scholarly journals Tailoring the anomalous Hall effect of SrRuO3 thin films by strain: A first principles study

2021 ◽  
Vol 129 (9) ◽  
pp. 093904
Author(s):  
Kartik Samanta ◽  
Marjana Ležaić ◽  
Stefan Blügel ◽  
Yuriy Mokrousov
Keyword(s):  
Thin Films ◽  
Hall Effect ◽  
First Principles ◽  
Anomalous Hall Effect ◽  
First Principles Study

First-Principles Total Energy Study of NbCr2 + V Laves Phase Ternary System

1998 ◽  
Vol 552 ◽  
Author(s):  
Alim Ormeci ◽  
S. P. Chen ◽  
John M. Wills ◽  
R. C. Albers
Keyword(s):  
Ternary System ◽  
Total Energy ◽  
Density Of States ◽  
First Principles ◽  
Laves Phase ◽  
Full Potential ◽  
Self Consistent ◽  
Substitutional Defects ◽  
Cohesive Energies ◽  
Formation Energies

ABSTRACTThe C15 NbCr2 + V Laves phase ternary system is studied by using a first-principles, self-consistent, full-potential total energy method. Equilibrium lattice parameters, cohesive energies, density of states and formation energies of substitutional defects are calculated. Results of all these calculations show that in the C15 NbCr2 + V compounds, V atoms substitute Cr atoms only.

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