Atomic and electronic structures of Mg-doped perfect SrTiO3 and crystals containing oxygen vacancies from first principles

2011 ◽  
Vol 406 (8) ◽  
pp. 1420-1428 ◽  
Author(s):  
Wen Zeng ◽  
Tian-mo Liu ◽  
Cheng-ling Lv ◽  
De-jun Liu
Keyword(s):  
First Principles ◽  
Electronic Structures ◽  
Oxygen Vacancies ◽  
Mg Doped

First-principles investigation of the conductive filament configuration in rutile TiO2-x ReRAM

2012 ◽  
Vol 1430 ◽  
Author(s):  
Liang Zhao ◽  
Seong-Geon Park ◽  
Blanka Magyari-Köpe ◽  
Yoshio Nishi
Keyword(s):  
High Resistance ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Conductive Filament ◽  
Low Resistance ◽  
Vacancy Ordering ◽  
Calculation Results ◽  
Resistance State

ABSTRACTThe interactions and ordering of oxygen vacancies in rutile TiO2 were thoroughly investigated by density functional calculations to search for atomic configurations of the conductive filament. As random isolated vacancies could not support the low-resistance state conduction in TiO2 ReRAM, vacancy ordering was introduced in [110] and [001] directions of the lattice to study the electronic structures. The calculation results revealed that a di-vacancy chain in [001] direction makes the electrons delocalized in that direction, which is identified as a possible configuration of the conductive filament. This low-resistance state can be effectively disrupted by moving oxygen vacancies out of the filament to reach high-resistance states.

Study of the Non-Linearity on TiO2(0 0 1) Surface with Oxygen Defects: A First-Principles Study

NANO ◽  
2017 ◽  
Vol 12 (08) ◽  
pp. 1750097
Author(s):  
Yuehua Dai ◽  
Xu Zhang ◽  
Chengzhi Ma ◽  
Zhiyong Pan ◽  
Feifei Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
First Principles ◽  
Electronic Structures ◽  
Oxygen Vacancies ◽  
Stark Effect ◽  
Energy Levels ◽  
Oxygen Interstitial ◽  
Oxygen Defects ◽  
Pseudopotential Calculations

First-principles plane-wave pseudopotential calculations were performed to study the energetics and electronic structures of oxygen defects on rutile TiO2(0 0 1). The influence of the material thickness on non-linearity (NL) was studied. With the increase in the thickness, the NL became stronger. Calculating the site-projected density of states by applying an external electric field showed that the NL of the bulk is due to the exchange of electrons between O 2p orbitals and Ti 3d orbitals. Finally, the influence of oxygen defects — oxygen vacancies (Vo), oxygen interstitials (Oi), and oxygen vacancies/oxygen interstitial (Vo[Formula: see text]Oi) pairs (Frenkel pair defects) — on the NL of TiO2 was studied. These results demonstrate that the band gap ([Formula: see text] of TiO2 became gradually narrower as the electric field increased. The Stark effect and defects can lead to the splitting of degenerate energy levels. Stronger electric fields increase the band splitting and reduce [Formula: see text]. With the increase in the Vo concentration, the decrease in the splitting amplitude and width of the energy level lead to weakening of the transfer of electrons between O and Ti atoms and optimizing the NL of TiO2. Therefore, the incorporation of Vo plays a significant role in improving the NL of TiO2.

scholarly journals First-principles study of electronic structures and electrochemical properties for Al, Fe and Mg doped Li2MnSiO4

2015 ◽  
Vol 64 (8) ◽  
pp. 087101
Author(s):  
Jia Ming-Zhen ◽  
Wang Hong-Yan ◽  
Chen Yuan-Zheng ◽  
Ma Cun-Liang ◽  
Wang Hui
Keyword(s):  
Electrochemical Properties ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Study ◽  
Mg Doped

First-principles study on the magnetic properties in Mg doped BiFeO3 with and without oxygen vacancies

2013 ◽  
Vol 114 (23) ◽  
pp. 233912 ◽  
Author(s):  
Ruipeng Yang ◽  
Sixian Lin ◽  
Xiaogong Fang ◽  
Xingsen Gao ◽  
Min Zeng ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Oxygen Vacancies ◽  
First Principles Study ◽  
Mg Doped

FIRST-PRINCIPLES STUDY OF OXYGEN-VACANCY Cu2O (111) SURFACE

2012 ◽  
Vol 11 (06) ◽  
pp. 1261-1280 ◽  
Author(s):  
HUANWEN WU ◽  
NING ZHANG ◽  
HONGMING WANG ◽  
SANGUO HONG
Keyword(s):  
Oxygen Vacancy ◽  
Electronic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Oxygen Vacancies ◽  
Vacancy Formation ◽  
First Principles Calculations ◽  
First Principles Study ◽  
Formation Energies ◽  
Geometric And Electronic Properties

Geometric and electronic properties and vacancy formation energies for two kinds of oxygen-vacancy Cu 2 O (111) surfaces have been investigated by first-principles calculations. Results show that the relaxation happens mainly on the top three trilayers of surfaces. Two vacancies trap electrons of -0.11e and -0.27e, respectively. The effects of oxygen vacancies on the electronic structures are found rather localized. The electronic structures suggest that the oxygen vacancies enhance the electron donating ability of the surfaces to some extent. The energies of 1.75 and 1.43 eV for the formation of oxygen vacancies are rather low, which indicates the partially reduced surfaces are stable and easy to produce.

scholarly journals Novel structural phases and the properties of LaX (X = P, As) under high pressure: first-principles study

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 3058-3070
Author(s):  
Yu Zhou ◽  
Lan-Ting Shi ◽  
A-Kun Liang ◽  
Zhao-Yi Zeng ◽  
Xiang-Rong Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Pressure Range ◽  
Mechanical Stability ◽  
First Principles Study

The structures, phase transition, mechanical stability, electronic structures, and thermodynamic properties of lanthanide phosphates (LaP and LaAs) are studied in the pressure range of 0 to 100 GPa by first principles.

Magnetism and electronic structures of bismuth (stannum) films at the CrI3 (CrBr3) interface

2021 ◽  
Vol 23 (7) ◽  
pp. 4255-4261
Author(s):  
Li Chen ◽  
Chuan Jiang ◽  
Maoyou Yang ◽  
Tao Hu ◽  
Yan Meng ◽  
...  
Keyword(s):  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculations

From first-principles calculations, the magnetism and electronic structures of bilayer bismuth (stannum) films at the monolayer CrI3 (CrBr3) interface are studied.

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