Electronic Structure of the Layered Ferroelectric Perovskite SrBi2Ta2O9

1996 ◽  
Vol 433 ◽  
Author(s):  
J Robertson ◽  
C W Chen ◽  
W L Warren
Keyword(s):  
Conduction Band ◽  
Tight Binding ◽  
Valence Band Maximum ◽  
Fatigue Properties ◽  
Layered Perovskite ◽  
Band Maximum ◽  
Tight Binding Method ◽  
Electronic Response ◽  
S States ◽  
Ferroelectric Perovskite

AbstractThe band structure of the Bi layered perovskite SrBi2Ta2O9 (SBT) has been calculated by the tight binding method. We find both the valence and conduction band edges to consist of states primarily derived from the Bi-O layer rather than the perovskite Sr-Ta-O blocks. The valence band maximum arises from 0 p and some Bi s states, while the conduction band minimum consists of Bi p states, with a band gap of 5.1 eV. It is argued that the Bi-O layers largely control the electronic response of SBT while the ferroelectric response originates from the perovskite Sr-Ta-O block. Bi and Ta centered traps are calculated to be shallow, which may account in part for the excellent fatigue properties of SBT.

Electronic Structure and Surface Properties of SrBi2Ta2O9 and Related Oxides

1997 ◽  
Vol 493 ◽  
Author(s):  
J Robertson ◽  
C W Chen
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Conduction Band ◽  
Tight Binding ◽  
Schottky Barriers ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Edge States ◽  
Tight Binding Method ◽  
S States

ABSTRACTThe electronic structure of SrBi2Ta2O9 and related oxides such as SrBi2Nb2O9, Bi2WO6 and Bi3Ti4O12 have been calculated by the tight-binding method. In each case, the band gap is about 4.1 eV and the band edge states occur on the Bi-O layers and consist of mixed O p/Bi s states at the top of the valence band and Bi p states at the bottom of the conduction band. The main difference between the compounds is that Nb 5d and Ti 4d states in the Nb and Ti compounds lie lower than the Ta 6d states in the conduction band. The surface pinning levels are found to pin Schottky barriers 0.8 eV below the conduction band edge.

Antimony as A Passivant of Si(111) in the Si(111) (√3×√3)-Sb System

1992 ◽  
Vol 259 ◽  
Author(s):  
A. Hughes ◽  
T-H. Shen ◽  
C.C. Matthai
Keyword(s):  
Fermi Level ◽  
Valence Band ◽  
Density Of States ◽  
Surface State ◽  
Tight Binding ◽  
Valence Band Maximum ◽  
Electronic Density ◽  
Band Maximum ◽  
Electronic Density Of States ◽  
Tight Binding Method

ABSTRACTThe electronic density of states (DOS) for the Si(111) (√3×√3)-Sb system has been calculated using the tight binding method in the Extended Hiickel Approximation. We find that there is a gap of about 0.8eV between the valence band maximum (VBM) and a surface state. This is in contrast with the case of the unreconstructed (lxl) surface where the Fermi level lies at the surface state.

Structural and Electronic Structure of SnO2 by the First-Principle Study

2012 ◽  
Vol 725 ◽  
pp. 265-268 ◽  
Author(s):  
Minoru Oshima ◽  
Kenji Yoshino
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Valence Band ◽  
Conduction Band ◽  
Valence Band Maximum ◽  
First Principle ◽  
Band Maximum ◽  
First Principle Calculations ◽  
Calculation Results ◽  
Good Agreement

We performed first-principle calculations to investigate the effects of F, Cl and Sb impurities on the electronic properties of SnO2. We obtained, firstly, the electronic structure of SnO2, a valence band maximum of SnO2is an O 2p orbital and a conduction band minimum was an antibonding Sn 5s and O 2p orbitals dominantly. Secondly, those impurites doped SnO2was obtained the electronic structure. The F, Cl and Sb impurities as n-type dopants exhibited shallow donors. This calculation results were in good agreement with our prvious experiment that we obtained the low resistivity SnO2.

First-principle calculation of the electronic structure, DOS and effective mass TlInSe2

2017 ◽  
Vol 31 (14) ◽  
pp. 1750155 ◽  
Author(s):  
N. A. Ismayilova ◽  
G. S. Orudzhev ◽  
S. H. Jabarov
Keyword(s):  
Electronic Structure ◽  
Effective Mass ◽  
Valence Band ◽  
Conduction Band ◽  
Density Of States ◽  
Valence Band Maximum ◽  
First Principle ◽  
Band Maximum ◽  
Effective Masses ◽  
Structure Density

The electronic structure, density of states (DOS), effective mass are calculated for tetragonal TlInSe2 from first principle in the framework of density functional theory (DFT). The electronic structure of TlInSe2 has been investigated by Quantum Wise within GGA. The calculated band structure by Hartwigsen–Goedecker–Hutter (HGH) pseudopotentials (psp) shows both the valence band maximum and conduction band minimum located at the T point of the Brillouin zone. Valence band maximum at the T point and the surrounding parts originate mainly from 6s states of univalent Tl ions. Bottom of the conduction band is due to the contribution of 6p-states of Tl and 5s-states of In atoms. Calculated DOS effective mass for holes and electrons are [Formula: see text], [Formula: see text], respectively. Electron effective masses are fairly isotropic, while the hole effective masses show strong anisotropy. The calculated electronic structure, density of states and DOS effective masses of TlInSe2 are in good agreement with existing theoretical and experimental results.

scholarly journals A first-principles study of anionic (S) and cationic (V/Nb) doped Sr2Ta2O7 for visible light photocatalysis

RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 40922-40928 ◽  
Author(s):  
Yuman Peng ◽  
Zuju Ma ◽  
Junjie Hu ◽  
Kechen Wu
Keyword(s):  
Visible Light ◽  
Valence Band ◽  
Conduction Band ◽  
First Principles ◽  
Valence Band Maximum ◽  
Conduction Band Minimum ◽  
Visible Light Photocatalysis ◽  
Band Maximum ◽  
Co Doping ◽  
First Principles Study

In order to utilize the visible light to catalyze water, UV-active Sr2Ta2O7 is engineered via co-doping of S and V/Nb to shift the valence band maximum upward and conduction band minimum downward by approximately 1 eV, respectively.

Electronic Structure of Sr2RuO4

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1157-1162 ◽  
Author(s):  
C. Noce ◽  
M. Cuoco
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Tight Binding ◽  
Superconducting Phase ◽  
P Wave ◽  
Layered Perovskite ◽  
Hückel Theory ◽  
Wave Symmetry ◽  
Tight Binding Method ◽  
The One

We introduce a microscopic model for the compound Sr 2 RuO 4, which is at the present the only known layered-perovskite superconductor without copper. The one-particle Hamiltonian is deduced by means of an approach that combines the extended Hückel theory and the tight-binding method. Adding two-body terms to this Hamiltonian, as the local Coulomb interaction and the Hund coupling, the magnetic properties are determined. It is found that the system is close to a ferromagnetic instability and this result supports a superconducting phase with p -wave symmetry.

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