First principle investigations of the Pbnm phase BiFeO3, BiFe0.875Mn0.125O3 and Bi0.875X0.125Fe0.875Mn0.125O3 (XBFM) (X = Ce, Gd, Lu)

2017 ◽  
Vol 31 (32) ◽  
pp. 1750304 ◽  
Author(s):  
Ren Zhang ◽  
Yunhua Zhou ◽  
Yiyi Zhu ◽  
Yangyang Li ◽  
Liang Chu ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Loss Function ◽  
Magnetic Moment ◽  
First Principles ◽  
Magnetic Moments ◽  
First Principle ◽  
Reflectivity Spectrum ◽  
Densities Of States

The structural, magnetic, electronic and optical properties of Pbnm BiFeO[Formula: see text] (BFO), BiFe[Formula: see text]Mn[Formula: see text]O[Formula: see text] (BFM), Bi[Formula: see text]X[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] (XBFM) (X = Ce, Gd, Lu) have been investigated by the first principles within the PBE[Formula: see text]+[Formula: see text]U scheme. It is shown that the dopant Mn in the B sites and Ce (Gd, Lu) in the A sites improves the crystalline quality. The magnetic moments of Bi[Formula: see text]Ce[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] (CBFM) and Bi[Formula: see text]Gd[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] (GBFM) are 10 [Formula: see text] and 16 [Formula: see text] which mainly arises from the strongly localized unpaired 4f electrons of Ce and Gd, 3d electrons of Mn and Fe. While, as BFM, the magnetic moment of Bi[Formula: see text]Lu[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] (LBFM) is 9 [Formula: see text] indicating no effect on the magnetization is made by Lu for its full 4f states. The densities of states of the five systems hint that CBFM is metallic and BFM, GBFM, LBFM are still semiconductors. The metallic properties of CBFM arise from the hybridization between Ce-4f and Mn-3d states which leads the Mn [Formula: see text] states to be split into [Formula: see text] and [Formula: see text] lowering the bottom of the conduction band to cross the Fermi level. Furthermore, we also study the optical properties of Pbnm BiFeO[Formula: see text] (BFO), BiFe[Formula: see text]Mn[Formula: see text]O[Formula: see text] (BFM), Bi[Formula: see text]X[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] (XBFM) (X = Ce, Gd, Lu). In this work, the optical properties including the absorption spectrum, loss function, refractive index and reflectivity spectrum are discussed in detail.

First-principle studies of the optoelectronic properties of ASnF3 (A = Na, K, Rb and Cs)

2017 ◽  
Vol 31 (21) ◽  
pp. 1750148 ◽  
Author(s):  
Imad Khan ◽  
Nasir Shehzad ◽  
Iftikhar Ahmad ◽  
Zahid Ali ◽  
S. Jalali-Asadabadi
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Energy Loss ◽  
Ab Initio Calculations ◽  
Loss Function ◽  
Electron Transition ◽  
First Principle ◽  
Electronic Band ◽  
New Type ◽  
Electronic Band Structures

In this paper, we communicate a new type of Auger-free luminescence (AFL) compounds, alkali tin fluorides ASnF3 (A = Na, K, Rb and Cs). The luminescence in these compounds originates due to the electron transition from the top valence band (VB) of tin-[Formula: see text] orbital to the outermost core levels of halogen, i.e., halogen-[Formula: see text] orbital ([Formula: see text]-[Formula: see text] transitions). The AFL of these compounds is expected to be of L-type. Furthermore, the electronic band structures and optical properties such as dielectric functions, refractive index and energy loss function are also investigated using ab initio calculations.

Study of Electronic and Optical Properties of PbS

2012 ◽  
Vol 476-478 ◽  
pp. 1154-1158
Author(s):  
Jin Ju Du ◽  
Wei Li
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
First Principles ◽  
Narrow Band ◽  
Energy Band Structure ◽  
First Principles Calculations ◽  
Density Of State ◽  
Reflectivity Spectrum ◽  
Electronic And Optical Properties

The electronic and optical properties of the lead sulfide are studied using first-principles calculations. The energy band structure and density of state of PbS are calculated. The results suggest that PbS exhibit a narrow band gap. The Mulliken analysis shows that the Pb-S bond is ionic. The dielectric function, absorption coefficient, reflectivity spectrum, refractive index and extinction coefficient are calculated for radiation up to 35eV. We have show that S (3p) electrons states and Pb (6p) electrons states play an important role in these transitions.

First-Principles Study of Structural, Electronic and Optical Properties in BaTi0.5Ni0.5O3

2013 ◽  
Vol 834-836 ◽  
pp. 268-271
Author(s):  
Hong Liang Pan ◽  
Shi Liang Yang ◽  
Teng Li
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
First Principles ◽  
Energy Band Structure ◽  
Generalized Gradient ◽  
Electronic And Optical Properties ◽  
Generalized Gradient Approximation ◽  
Structure Density ◽  
Pseudo Potential

The pseudo-potential plane wave (PP-PW) mehod with the generalized gradient approximation (GGA) is applied to study the electronic and optical properties of BaTi0.5Ni0.5O3. The energy band structure, density of states (DOS) are obtained. The optical properties including the dielectric function, reflectivity, absorption spectrum, extinction coefficient, energy-loss spectrum and refractive index are also calculated and analyzed in detail.

Effect of Hydrogen Coverage on Elastic and Optical Properties of Silicene: A First-Principle Study

2021 ◽  
Author(s):  
Santosh Routu ◽  
Jagan Mohana Rao Malla ◽  
Suresh Yathirajula ◽  
Nageswar rao Uppala
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
First Principles ◽  
Visible Range ◽  
Optical Parameters ◽  
First Principle ◽  
Plasmon Energy ◽  
Estimated Parameters ◽  
First Time ◽  
Constant Refractive Index

Abstract The structural, electronic, and optical properties of hydrogenated silicene have been investigated using first-principles DFT calculations. In comparison to pristine silicene, the hydrogenated silicene exhibits high stability, reduced anisotropy, and less birefringence. In the visible range, hydrogenated silicene exhibits a constant refractive index than silicene. The elastic and optical parameters: Young’s modulus (Y), poisson’s ratio (ν), bulk modulus (B), shear modulus (G), dielectric constant ε(0), refractive index n(0), conductivity threshold (Eth), birefringence Δn(0), and plasmon energy (ħωp) were calculated for the first time for various hydrogen occupancy levels. The estimated parameters are agree well with the experimental and reported values that are available.

First-Principles Calculations on Structural, Electronic, and Optical Properties of 2H-CuAlO2

2011 ◽  
Vol 197-198 ◽  
pp. 487-490 ◽  
Author(s):  
Li Ping Feng ◽  
Zheng Tang Liu ◽  
Qi Jun Liu
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Lattice Parameters ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Charge Densities ◽  
Densities Of States

Structural, electronic and optical properties of 2H-CuAlO2 were computed, using the plane-wave ultrasoft pseudopotential technique based on the first-principles density functional theory (DFT). The equilibrium lattice parameters, band structure, densities of states (DOS) and charge densities of 2H-CuAlO2 have been obtained. The equilibrium lattice parameters, band structure and DOS are found to be in good agreement with the available experimental and calculational values. The charge densities and the chemical bonding of 2H-CuAlO2 are analyzed, which show that bonding between Cu and O is mainly covalent due to Cu 3d and O 2p hybridization and that bonding between Al and O is mainly ionic. The complex dielectric function, refractive index and absorption coefficient of 2H-CuAlO2 have been predicted. The calculated static dielectric constant and static refractive index of 2H-CuAlO2 is 7.1 and 2.66, respectively.

scholarly journals Spin Polarization Properties of Pentagonal PdSe2 Induced by 3D Transition-Metal Doping: First-Principles Calculations

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2339 ◽  
Author(s):  
Xiuwen Zhao ◽  
Bin Qiu ◽  
Guichao Hu ◽  
Weiwei Yue ◽  
Junfeng Ren ◽  
...  
Keyword(s):  
Transition Metal ◽  
Spin Polarization ◽  
First Principles ◽  
Magnetic Moments ◽  
First Principles Calculations ◽  
Density Distributions ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Theoretical Investigations ◽  
Densities Of States

The electronic structure and spin polarization properties of pentagonal structure PdSe2 doped with transition metal atoms are studied through first- principles calculations. The theoretical investigations show that the band gap of the PdSe2 monolayer decreases after introducing Cr, Mn, Fe and Co dopants. The projected densities of states show that p-d orbital couplings between the transition metal atoms and PdSe2 generate new spin nondegenerate states near the Fermi level which make the system spin polarized. The calculated magnetic moments, spin density distributions and charge transfer of the systems suggest that the spin polarization in Cr-doped PdSe2 will be the biggest. Our work shows that the properties of PdSe2 can be modified by doping transition metal atoms, which provides opportunity for the applications of PdSe2 in electronics and spintronics.

scholarly journals Spin Gapless Semiconductor–Nonmagnetic Semiconductor Transitions in Fe-Doped Ti2CoSi: First-Principle Calculations

2018 ◽  
Vol 8 (11) ◽  
pp. 2200 ◽  
Author(s):  
Yu Feng ◽  
Zhou Cui ◽  
Ming-sheng Wei ◽  
Bo Wu ◽  
Sikander Azam
Keyword(s):  
Magnetic Moment ◽  
Electronic Structures ◽  
Magnetic Moments ◽  
Total Magnetic Moment ◽  
First Principle ◽  
Half Metallic ◽  
Heusler Compound ◽  
First Principle Calculations ◽  
Metallic Ferromagnet

Employing first-principle calculations, we investigated the influence of the impurity, Fe atom, on magnetism and electronic structures of Heusler compound Ti2CoSi, which is a spin gapless semiconductor (SGS). When the impurity, Fe atom, intervened, Ti2CoSi lost its SGS property. As TiA atoms (which locate at (0, 0, 0) site) are completely occupied by Fe, the compound converts to half-metallic ferromagnet (HMF) TiFeCoSi. During this SGS→HMF transition, the total magnetic moment linearly decreases as Fe concentration increases, following the Slate–Pauling rule well. When all Co atoms are substituted by Fe, the compound converts to nonmagnetic semiconductor Fe2TiSi. During this HMF→nonmagnetic semiconductor transition, when Fe concentration y ranges from y = 0.125 to y = 0.625, the magnetic moment of Fe atom is positive and linearly decreases, while those of impurity Fe and TiB (which locate at (0.25, 0.25, 0.25) site) are negative and linearly increase. When the impurity Fe concentration reaches up to y = 1, the magnetic moments of Ti, Fe, and Si return to zero, and the compound is a nonmagnetic semiconductor.

First Principles Calculation of Geometrical and Electronic Structure of Semiconductor Fe1-xMnxSi2

2011 ◽  
Vol 213 ◽  
pp. 483-486
Author(s):  
Fang Gui ◽  
Shi Yun Zhou ◽  
Wan Jun Yan ◽  
Chun Hong Zhang ◽  
Xiao Tian Guo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Function Theory ◽  
Density Function Theory ◽  
First Principles Calculation ◽  
First Principle ◽  
Substitutional Doping ◽  
Pseudo Potential ◽  
Mn Concentrations

The electronic structure and optical properties of Fe1-xMnxSi2 have been studied using the first principle plane-wave pseudo-potential based on the density function theory. Substitutional doping is considered with Mn concentrations of x=0.0625, 0.125, 0.1875 and 0.25, respectively. The calculated results show that the volume of β-FeSi2 increase and the band gap increase with increasing of Mn.

scholarly journals First principles study of structure, electronic and optical properties of Y3Fe5O12 in cubic and trigonal phases

2015 ◽  
Vol 33 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Shen Tao ◽  
Hu Chao ◽  
Dai Hailong ◽  
Yang Wenlong ◽  
Liu Hongchen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Energy Loss ◽  
First Principles ◽  
Structural Parameters ◽  
Band Gaps ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Band ◽  
Experimental Values

AbstractFirst principles calculations have been performed to investigate the structure, electronic and optical properties of Y3Fe5O12. Both the cubic and trigonal phases have been considered in our calculation. The calculated structural parameters are slightly larger than the experimental values. The band structures show that Y3Fe5O12 in cubic and trigonal phases have direct band gaps of 0.65 and 0.17 eV. The calculations of dielectric function, absorption, extinction coefficient, refractive index, energy loss function and reflectivity are presented.

A first-principles study of the effects of different Al constituents on Ga1−xAlxN nanowires

2016 ◽  
Vol 30 (30) ◽  
pp. 1650217 ◽  
Author(s):  
Sihao Xia ◽  
Lei Liu ◽  
Yike Kong ◽  
Honggang Wang ◽  
Meishan Wang
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Plane Wave ◽  
First Principles ◽  
Formation Energy ◽  
High Energy ◽  
Dielectric Constants ◽  
Interesting Phenomenon ◽  
Densities Of States ◽  
Static Dielectric Constants

In order to investigate the influences of different Al constituents on Ga[Formula: see text]Al[Formula: see text]N nanowires, the formation energy, stability, band structure, densities of states and optical properties of Ga[Formula: see text]Al[Formula: see text]N nanowires with different Al constituents are calculated using first-principles plane-wave ultrasoft pseudopotential method. Results show that Ga[Formula: see text]Al[Formula: see text]N nanowires become more stable with increasing Al constituent. Bandgap of Ga[Formula: see text]Al[Formula: see text]N nanowires increases as the Al constituent increases but with a lower amplification compared with bulk Ga[Formula: see text]Al[Formula: see text]N. The peaks of static dielectric constants show a decreasing trend and move towards high-energy side as Al constituent increases. The absorption of Ga[Formula: see text]Al[Formula: see text]N nanowires shows an interesting phenomenon that it firstly increases and then decreases slightly as the Al constituent increases. Reflectivity of Ga[Formula: see text]Al[Formula: see text]N nanowires is much smaller than that of the bulk. The optical properties of Ga[Formula: see text]Al[Formula: see text]N nanowires show a blueshift effect as Al composition increases. According to these calculations, it is found that Ga[Formula: see text]Al[Formula: see text]N nanowires are appropriate to be applied into photoelectric detecting materials by adjusting the Al constituent of Ga[Formula: see text]Al[Formula: see text]N nanowires.

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