scholarly journals Structural and electronic properties of boron- bismuth compound under pressure

2016 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
Salah Daoud ◽  
Noudjoud Labgaa

<p>In the present work, we report first principles calculations of the pressure effect on the structural and electronic properties of Boron- Bismuth (BBi) compound in its zincblende phase. The pseudopotential plane wave (PPW) method in the framework of the density func-tional theory (DFT) within the local density approximation for the exchange-correlation functional, and the Hartwigzen-Goedecker-Hutter (HGH) scheme for the pseudopotential were used in the calculation. The unit cell volume, the molecular and crystal densities, the equation of state and also the linear and quadratic pressure coefficients of the energy band-gaps are investigated.</p>

2019 ◽  
Vol 16 (2) ◽  
pp. 77 ◽  
Author(s):  
Muhammad Zamir Mohyedin ◽  
Afiq Radzwan ◽  
Mohammad Fariz Mohamad Taib ◽  
Rosnah Zakaria ◽  
Nor Kartini Jaafar ◽  
...  

Bi2Se3 is one of the promising materials in thermoelectric devices and very useful out of environmental concern due to its efficiency to perform at room temperature. Based on the first-principles calculation of density functional theory (DFT) by using CASTEP computer code, structural and electronic properties of Bi2Se3 were investigated. The calculation is conducted within the exchange-correlation of local density approximation (LDA) and generalized gradient approximation within the revision of Perdew-Burke-Ernzerhof (GGA-PBE) functional. It was found that the results are consistent with previous works of theoretical study with small percentage difference. LDA exchange-correlation functional method is more accurate and have a better agreement than GGA-PBE to describe the structural properties of Bi2Se3 which consist of lattice parameters. LDA functional also shown more accurate electronic structure of Bi2Se3 that consist of band structure and density of states (DOS) which consistent with most previous theoretical works with small percentage difference. This study proves the reliability of CASTEP computer code and show LDA exchange-correlation functional is more accurate in describing the nature of Bi2Se3 compared to the other functionals.


2013 ◽  
Vol 700 ◽  
pp. 79-82
Author(s):  
Guo Xiang Chen ◽  
Dou Dou Wang

We have performed the first-principles calculations onto the structural and electronic properties of GaN nanoribbons with zigzag edge (ZGaNNRs). The results show that, the lowest unoccupied conduction band (LUCB) and the highest occupied valence band (HOVB) are always separated, representing a semiconductor character for the ZGaNNRs. In addition, the majority and minority spin bands are fully superposition and therefore the ZGaNNRs are non-magnetic. As the nanoribbons width increase, band gaps of ZGaNNRs decrease monotonically and become close to their asymptotic limit of a single layer of GaN sheet. It is found that the fewer coordination number will lead the most electrons to range in higher energy region of the occupancy state.


2016 ◽  
Vol 27 (03) ◽  
pp. 1650035 ◽  
Author(s):  
Rezek Mohammad ◽  
Şenay Katırcıoğlu

Structural stability and electronic properties of GaAs[Formula: see text]P[Formula: see text] ([Formula: see text]) nanowires (NWs) in zinc-blende (ZB) ([Formula: see text] diameter [Formula: see text][Formula: see text]Å) and wurtzite (WZ) ([Formula: see text][Formula: see text]Å) phases are investigated by first-principles calculations based on density functional theory (DFT). GaAs ([Formula: see text]) and GaP ([Formula: see text]) compound NWs in WZ phase are found energetically more stable than in ZB structural ones. In the case of GaAs[Formula: see text]P[Formula: see text] alloy NWs, the energetically favorable phase is found size and composition dependent. All the presented NWs have semiconductor characteristics. The quantum size effect is clearly demonstrated for all GaAs[Formula: see text]P[Formula: see text] ([Formula: see text]) NWs. The band gaps of ZB and WZ structural GaAs compound NWs with [Formula: see text] diameter [Formula: see text][Formula: see text]Å and [Formula: see text][Formula: see text]Å, respectively are enlarged by the addition of concentrations of phosphorus for obtaining GaAs[Formula: see text]P[Formula: see text] NWs proportional to the x values around 0.25, 0.50 and 0.75.


2009 ◽  
Vol 1204 ◽  
Author(s):  
T. Urakawa ◽  
K. Shintani

AbstractThe structural and electronic properties of graphene nanoribbons (GNRs) modified by H, CO, and NH3 molecules at their edges under uniaxial strain is investigated by means of first principles calculations. It is found the bond length of the reconstructed edge of a H-terminated GNR modified by CO is larger than those of a bare GNR, a H-terminated GNR, and a H-terminated GNR modified by NH3. It is also found the band gaps of a H-terminated GNR and a H-terminated GNR modified by CO are twice the gap of a bare GNR, and the band gaps of a bare GNR and a H-terminated GNR increase with the increase of imposed strain.


2010 ◽  
Vol 24 (24) ◽  
pp. 4851-4859
Author(s):  
KAIHUA HE ◽  
GUANG ZHENG ◽  
GANG CHEN ◽  
QILI CHEN ◽  
MIAO WAN ◽  
...  

The structural and electronic properties of BN(5, 5) and C(5, 5) nanotubes under pressure are studied by using first principles calculations. In our study range, BN(5, 5) undergoes obvious elliptical distortion, while for C(5, 5) the cross section first becomes an ellipse and then, under further pressure, is flattened. The band gap of BN(5, 5) decreases with increasing pressure, which is inverse to that of zinc blende BN, whereas for C(5, 5) the metallicity is always preserved under high pressure. The population of charge density indicates that intertube bonding is formed under pressure. We also find that BN(5, 5) may collapse, and a new polymer material based on C(5, 5) is formed by applying pressure.


2021 ◽  
Author(s):  
Thi Nga Do ◽  
Son-Tung Nguyen ◽  
Khang Pham

In this work, by means of the first-principles calculations, we investigate the structural and electronic properties of a two-dimensional ZnGeN2 monolayer as well as the effects of strains and electric...


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