Substitutional site of Mn4+ ion and local compressibility of this Mn4+ center in Mn4+-doped Sr4Al14 O25 crystal

2019 ◽  
Vol 174 (7-8) ◽  
pp. 687-690
Author(s):  
Xiao-Xuan Wu ◽  
Min Cheng
Keyword(s):  
Substitutional Site

First-Principles Analysis on Interaction between Dopant (Ga, Sb) and Contamination Metal Atoms in Ge Crystals

2013 ◽  
Vol 205-206 ◽  
pp. 417-421
Author(s):  
Tatsunori Yamato ◽  
Koji Sueoka ◽  
Takahiro Maeta
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Binding Energies ◽  
Functional Theory ◽  
Substitutional Site ◽  
Metal Impurities ◽  
Metal Atoms ◽  
Total Energies ◽  
Group 3

The lowest energetic configurations of metal impurities in 4throw (Sc - Zn), 5throw (Y - Cd) and 6throw (Hf - Hg) elements in Ge crystals were determined with density functional theory calculations. It was found that the substitutional site is the lowest energetic configuration for most of the calculated metals in Ge. The most stable configurations of dopant (Ga, Sb) - metal complexes in Ge crystals were also investigated. Following results were obtained. (1) For Ga dopant, 1st neighbor T-site is the most stable for metals in group 3 to 7 elements while substitutional site next to Ga atom is the most stable for metals in group 8 to 12 elements. (2) For Sb dopant, substitutional site next to Sb atom is the most stable for all calculated metals. Binding energies of the interstitial metalMiwith the substitutional dopantDswere obtained by the calculated total energies. The calculated results for Ge were compared with those for Si.

scholarly journals DFT calculation for the electronic properties and quantum capacitance of pure and doped Zr2CO2 as electrode of supercapacitors

2021 ◽  
Author(s):  
Shuo Xu ◽  
Shi-Jie Wang ◽  
Li Xiao-Hong ◽  
Hong-Ling Cui
Keyword(s):  
Electronic Properties ◽  
Electrode Materials ◽  
Chemical Properties ◽  
Effect Of Temperature ◽  
Quantum Capacitance ◽  
Substitutional Site ◽  
Level Shifts ◽  
Dirac Distribution ◽  
Increasing Temperature ◽  
Physical And Chemical

Defect and doping are effective methods to modulate the physical and chemical properties of materials. In this report, we investigated the structural stability, electronic properties and quantum capacitance (Cdiff) of Zr2CO2 by changing the dopants of Si, Ge, Sn, N, B, S and F in the substitutional site. The doping of F, N, and S atoms makes the system undergo the semiconductor-to-conductor transition, while the doping of Si, Ge, and Sn maintains the semiconductor characteristics. The Cdiff of the doped systems are further explored. The B-doped system can be used as cathode materials, while the systems doped by S, F, N, Sn atoms are promising anode materials of asymmetric supercapacitors, especially for the S-doped system. The improved Cdiff mainly originates from Fermi-level shifts and Fermi-Dirac distribution by the introduction of the dopant. The effect of temperature on Cdiff is further explored. The result indicates that the maximum Cdiff of the studied systems gradually decreases with the increasing temperature. Our investigation can provide useful theoretical basis for designing and developing the ideal electrode materials for supercapacitors.

Theory of DX Centers in AlxGa1-x Alloys

1989 ◽  
Vol 163 ◽  
Author(s):  
D. J. Chadi ◽  
S. B. Zhang
Keyword(s):  
Theoretical Model ◽  
Ab Initio ◽  
Electronic Properties ◽  
Lattice Distortion ◽  
Substitutional Site ◽  
Ionization Energies ◽  
Dx Centers ◽  
Large Lattice ◽  
Self Consistent ◽  
Pseudo Potential

AbstractA theoretical model for DX centers which explains their unusual electronic properties in terms of two distinct bonding configurations for donor impurities in AlxGa1-x As alloys is examined. The results of our ab initio self-consistent pseudo-potential calculations show that for x > ≃20%, the normal fourfold coordinated substitutional site becomes unstable with respect to a large lattice distortion. The model explains the large difference between the thermal and optical ionization energies of DX centers.

scholarly journals Observation of Substitutional Site Preference in a Quasicrystal and Implication on Local Structure

1987 ◽  
Vol 59 (21) ◽  
pp. 2443-2446 ◽  
Author(s):  
M. Eibschütz ◽  
M. E. Lines ◽  
H. S. Chen ◽  
J. V. Waszczak ◽  
G. Papaefthymiou ◽  
...  
Keyword(s):  
Local Structure ◽  
Site Preference ◽  
Substitutional Site

Theoretical Study on Hole Compensation Mechanism: - Stability of Two Nitrogen Atoms at SE Substitutional Site of ZNSE -

1995 ◽  
Vol 196-201 ◽  
pp. 293-296
Author(s):  
Taketoshi Nakao ◽  
Masakatsu Suzuki ◽  
Takeshi Uenoyama ◽  
Yusuke Funayose
Keyword(s):  
Theoretical Study ◽  
Compensation Mechanism ◽  
Substitutional Site

First Principles Calculations of Helium Solution Energies in BCC Transition Metals

2006 ◽  
Vol 981 ◽  
Author(s):  
François Willaime ◽  
Chu Chun FU
Keyword(s):  
Transition Metals ◽  
Density Functional ◽  
Tetrahedral Site ◽  
Density Functional Theory Calculations ◽  
Interstitial Site ◽  
Group Vi ◽  
Functional Theory ◽  
Group V ◽  
Substitutional Site ◽  
Exchange Correlation

AbstractDensity functional theory calculations of the solution energies of helium in substitutional, tetrahedral and octahedral sites have been performed for all BCC transition metals: V, Nb, Ta, Cr, Mo, W and Fe. The effects of exchange correlation functional and of pseudopotential have been investigated in Fe; they are relatively small. The solution energies are found to be weakly dependent on the element for the substitutional site whereas for the interstitial sites they are much smaller in group V than in group VI and they decrease from 3d to 4d and 5d metals. As a result an inversion is observed from V, Nb and Ta - which tend to favor the interstitial site - to Mo and W, which favor the substitutional one, with an intermediate behavior for Cr and Fe. Finally, the results indicate that the tetrahedral site is always energetically more favorable than the octahedral one by 0.2 to 0.3 eV.

Substitutional site of Co2+ ions in GuGaS2:Co2+ crystal

1999 ◽  
Vol 60 (10) ◽  
pp. 1725-1727 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Shao-Yi Wu
Keyword(s):  
Substitutional Site

The Structure of the Boron-Hydrogen Complex in Silicon

1987 ◽  
Vol 104 ◽  
Author(s):  
A. D. Marwick ◽  
G. S. Oehrlein ◽  
J. H. Barrett ◽  
N. M Johnson
Keyword(s):  
Monte Carlo ◽  
Hydrogen Atom ◽  
Monte Carlo Simulations ◽  
Boron Atom ◽  
Small Proportion ◽  
Crystalline Silicon ◽  
Hydrogen Atoms ◽  
Substitutional Site ◽  
Bond Center ◽  
Center Site

ABSTRACTChanneling and lattice location has been used to investigate the structure of the boron-hydrogen complex in crystalline silicon. The positions of both the boron and hydrogen atoms have been determined. The results are compared with Monte-Carlo simulations. The boron atom in the B-H pair is found to be displaced from a substitutional site by 0.28±0.03Å, while the hydrogen atom is predominantly at a bond-center site, with a small proportion in a back-bonded position.

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