First-principles calculation of formation energies and electronic structures of hydrogen defects at tetrahedral and octahedral interstitial sites in pyrochlore-type Y2Ti2O7 oxide

2016 ◽  
Vol 678 ◽  
pp. 153-159 ◽  
Author(s):  
B. Tsuchiya ◽  
T. Yamamoto ◽  
K. Ohsawa ◽  
G.R. Odette
Keyword(s):  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculation ◽  
Hydrogen Defects ◽  
Pyrochlore Type ◽  
Formation Energies

scholarly journals Critical Thermodynamic Conditions for the Formation of p-Type β-Ga2O3 with Cu Doping

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5161
Author(s):  
Chuanyu Zhang ◽  
Zhibing Li ◽  
Weiliang Wang
Keyword(s):  
Oxygen Partial Pressure ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculation ◽  
Third Generation ◽  
Cu Doping ◽  
Thermodynamic Conditions ◽  
The Stability ◽  
P Type ◽  
Formation Energies

As a promising third-generation semiconductor, β-Ga2O3 is facing bottleneck for its p-type doping. We investigated the electronic structures and the stability of various Cu doped structures of β-Ga2O3. We found that Cu atoms substituting Ga atoms result in p-type conductivity. We derived the temperature and absolute oxygen partial pressure dependent formation energies of various doped structures based on first principles calculation with dipole correction. Then, the critical thermodynamic condition for forming the abovementioned substitutional structure was obtained.

Stability and Structures of Constitutional Defects in Nonstoichiometric Intermetallic Compounds by First-Principles Calculations

2005 ◽  
Vol 475-479 ◽  
pp. 3111-3114
Author(s):  
Masataka Mizuno ◽  
Hideki Araki ◽  
Yasuharu Shirai
Keyword(s):  
Intermetallic Compounds ◽  
First Principles ◽  
Electronic Structures ◽  
Stoichiometric Composition ◽  
Electronic Structure Calculations ◽  
First Principles Calculations ◽  
Compositional Dependence ◽  
Wide Range ◽  
Formation Energies ◽  
Structure Calculations

Some of intermetallic compounds exist in a wide range of concentration around the stoichiometric composition. First-principles electronic structure calculations have been performed for constitutional defects in non-stoichiometric CoAl and CoTi in order to investigate their stabilities and structural relaxations induced by constitutional defects. For the evaluation of stabilities of constitutional defects, the compositional dependence curves both of formation energies and of lattice parameters are obtained by the calculations employing supercells in various sizes. The lattice relaxations around constitutional defects are discussed by analyzing the change in electronic structures induced by constitutional defects.

First-Principles Calculations of Titanium Dopants in Alumina

2005 ◽  
Vol 475-479 ◽  
pp. 3095-3098
Author(s):  
Katsuyuki Matsunaga ◽  
Teruyasu Mizoguchi ◽  
Atsutomo Nakamura ◽  
Takahisa Yamamoto ◽  
Yuichi Ikuhara
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculations ◽  
Pseudopotential Calculations ◽  
Formation Energies

First-principles pseudopotential calculations were performed to investigate atomic and electronic structures of titanium (Ti) dopants in alumina (Al2O3). It was found that a substitutional Ti3+ defect induced an extra level occupied by one electron within the band gap of Al2O3. When two or more substitutional Ti3+ defects were located closely to each other, the defect-induced levels exhibited strong bonding interactions, and their formation energies decreased with increasing numbers of Ti3+ defects. This indicates that association and clustering of substitutional Ti3+ defects in Al2O3 can take place due to the interaction of the defect-induced levels.

Electronic and optical properties of hydrogen-terminated biphenylene nanoribbon：a first-principles study

2021 ◽  
Author(s):  
Hong Shen ◽  
Riyi Yang ◽  
Kun Xie ◽  
Zhiyuan Yu ◽  
Yuxiang Zheng ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculation ◽  
Electronic And Optical Properties ◽  
First Principles Study

The electronic structures and optical properties of novel 2D biphenylene and hydrogen-terminated nanoribbons of different widths which are cut from a layer of biphenylene were explored by first-principles calculation. The...

Investigation on the electronic structures and optical performances of Si–S codoped anatase TiO 2 by first-principles calculation

2016 ◽  
Vol 380 (16) ◽  
pp. 1462-1468 ◽  
Author(s):  
S.W. Zhou ◽  
P. Peng ◽  
J. Liu ◽  
Y.H. Tang ◽  
B. Meng ◽  
...  
Keyword(s):  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculation

First-Principles Study on Elastic Anomalies in Ag/Al Multilayers

2007 ◽  
Vol 345-346 ◽  
pp. 959-962
Author(s):  
Yusuke Kinoshita ◽  
Yoshitaka Umeno ◽  
Takayuki Kitamura
Keyword(s):  
Electronic Structure ◽  
Elastic Constant ◽  
First Principles ◽  
Electronic Structures ◽  
Interplanar Spacing ◽  
First Principles Calculation ◽  
Mixing Rule ◽  
Modulation Period ◽  
The Difference ◽  
Elastic Anomalies

Using the first-principles calculation, the elastic constant C44 of Ag/Al multilayers with different modulation periods from 0.43 nm to 2.27 nm has been evaluated in order to examine the effect of atomic and electronic structures on it. With increasing modulation period, C44 decreases and becomes close to that obtained by the conventional mixing rule, however, the difference of 8 % still remains at the modulation period of 2.27 nm. As C44 correlates with the average interplanar spacing, the decrease of C44 can be explained by the decrease of the charge density in the stacking direction due to the increase of the average interplanar spacing. The difference in the electronic structure is included in the effect of atomic structure.

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