scholarly journals Energetics and Configurations of Lattice Defects in CuTi

1990 ◽  
Vol 193 ◽  
Author(s):  
James R. Shoemaker ◽  
David Wesley ◽  
William R. Wharton ◽  
Michael L. Oehrli ◽  
Michael J. Sabochick ◽  
...  
Keyword(s):  
Atomistic Simulation ◽  
Antisite Defect ◽  
Lattice Defects ◽  
Two Dimensional ◽  
Antisite Defects

ABSTRACTThe energies and configurations of interstitials and vacancies in the ordered compound CuTi were calculated using atomistic simulation. Vacancies created by the removal of either a Cu or Ti atom resulted in a vacant Cu site, with an antisite defect in the latter case. The vacancy at the Cu site was found to be very mobile within two adjacent (001) Cu planes, resulting in two dimensional migration. Interstitials created by inserting either a Cu or Ti atom had complicated configurations containing one or more antisite defects.

Point defect study of CuTi and CuTi2

1991 ◽  
Vol 6 (3) ◽  
pp. 473-482 ◽  
Author(s):  
J.R. Shoemaker ◽  
R.T. Lutton ◽  
D. Wesley ◽  
W.R. Wharton ◽  
M.L. Oehrli ◽  
...  
Keyword(s):  
Atomistic Simulation ◽  
Formation Energy ◽  
Antisite Defect ◽  
Two Dimensional ◽  
Migration Energy ◽  
Vacancy Migration ◽  
Embedded Atom ◽  
Antisite Defects ◽  
Formation Energies ◽  
Vacancy Migration Energy

The energies and configurations of interstitials and vacancies in the ordered compounds CuTi and CuTi2 were determined using atomistic simulation with realistic embedded-atom potentials. The formation energy of an antisite pair was found to be 0.385 and 0.460 eV in CuTi and CuTi2, respectively. In both compounds, the creation of a vacancy by the removal of either a Cu or Ti atom resulted in a vacant Cu site, with an adjacent antisite defect in the case of the Ti vacancy. The vacant Cu site in CuTi was found to be very mobile within two adjacent (001) Cu planes, with a migration energy of 0.19 eV, giving rise to two-dimensional migration. The vacancy migration energy across (001) Ti planes, however, was 1.32 eV, which could be lowered to 0.75 or 0.60 eV if one or two Cu antisite defects were initially present in these planes. In CuTi2, the vacancy migration energy of 0.92 eV along the (001) Cu plane was significantly higher than in CuTi. The effective vacancy formation energies were calculated to be 1.09 eV and 0.90 eV in CuTi and CuTi2, respectively. Interstitials created by inserting either a Cu or Ti atom had complicated configurations in which a Cu 〈111〉 split interstitial was surrounded by two or three Ti antisite defects. The interstitial formation energy was estimated to be 1.7 eV in CuTi and 1.9 eV in CuTi2.

scholarly journals Calculation of Defect Properties of NiTi and FeTi

1990 ◽  
Vol 209 ◽  
Author(s):  
Russell T. Lutton ◽  
Michael J. Sabochick ◽  
Nghi Q. Lam
Keyword(s):  
Atomistic Simulation ◽  
Antisite Defect ◽  
Vacancy Formation ◽  
Stable Configuration ◽  
Antisite Defects ◽  
Formation Energies

ABSTRACTThe energies and configurations of interstitials and vacancies in the B2 ordered compounds NiTi and FeTi were calculated using atomistic simulation. The stable configuration of a vacancy after the removal of an Ni atom was a vacant Ni site; similarly, the removal of an Fe atom in FeTi resulted in a vacant Fe site. Removal of a Ti atom in both compounds, however, resulted in a vacant Ni or Fe site and an adjacent antisite defect. The effective vacancy formation energies in NiTi and FeTi were calculated to be 1.48 and 1.07 eV, respectively. Interstitials in NiTi formed split <111> configurations consisting of a Ni-Ni dumbbell oriented in the <111> direction with one or two adjacent antisite defects. The Fe interstitial in FeTi had a similar configuration, except the dumbbell contained Fe atoms. The Ti interstitial in FeTi formed an <110> Fe-Fe dumbbell.

EL2 and gallium antisite defects in GaAs: Si

1989 ◽  
Vol 67 (4) ◽  
pp. 375-378 ◽  
Author(s):  
C. K. Teh ◽  
F. L. Weichman ◽  
C. C. Tin ◽  
P. A. Barnes
Keyword(s):  
Fourier Transform ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Fourier Transform Infrared ◽  
Antisite Defect ◽  
Longitudinal Optic ◽  
Related Defect ◽  
Antisite Defects ◽  
Transient Spectroscopy ◽  
Silicon Doped

Photoluminescence (PL), Fourier-transform infrared (FTIR), and deep-level transient spectroscopy (DLTS) measurements have been made on various samples of silicon-doped liquid-encapsulated Czochralski-grown GaAs. All the samples show prominent PL peaks at 1.443 and 1.325 eV together with their longitudinal optic (LO) phonon peaks. The PL peak at 1.443 eV has been reported in the literature as being due to either GaAs or a boron-related defect. The FTIR results show the presence of BGa at 540.3 and 517.0 cm−1 and SiGa at 383.6 cm−1. We have observed that there is no correlation between the PL peak at 1.443 eV and BGa. Thus, we believe that this PL peak is related to the GaAs antisite defect. The presence of EL2 in the samples has been measured using DLTS. We have found that the intensity of the PL peak at 1.443 eV varies inversely with that of the EL2 peak. This relationship indirectly confirms that the 1.443 eV peak is due to the gallium antisite defect. The PL peak at 1.325 eV is significantly different from those reported in the literature for GaAs:Si. Measurements have also been made on samples of GaAs:Si annealed under different arsenic overpressures.

Patching of Lattice Defects in Two-Dimensional Diffusion Barriers

2018 ◽  
Vol 1 (7) ◽  
pp. 3068-3074
Author(s):  
Damon B. Farmer ◽  
Priscilla D. Antunez ◽  
Marinus Hopstaken ◽  
Oki Gunawan ◽  
Shu-Jen Han
Keyword(s):  
Diffusion Barriers ◽  
Lattice Defects ◽  
Two Dimensional ◽  
Dimensional Diffusion

Identification of the Negative Di-Carbon Antisite Defect in n-Type 4H-SiC

2009 ◽  
Vol 615-617 ◽  
pp. 361-364
Author(s):  
Adam Gali ◽  
T. Umeda ◽  
Erik Janzén ◽  
Norio Morishita ◽  
Takeshi Ohshima ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
First Principles ◽  
Annealing Temperature ◽  
Antisite Defect ◽  
First Principles Calculations ◽  
Electron Dose ◽  
Paramagnetic Resonance ◽  
Antisite Defects ◽  
The Creation ◽  
Electron Paramagnetic

We identify the negatively charged dicarbon antisite defect (C2 core at silicon site) in electron irradiated n-type 4H-SiC by means of combined electron paramagnetic resonance (EPR) studies and first principles calculations. The pair of HEI5 and HEI6 EPR centers (S = 1/2, C1h symmetry) are associated with the cubic and hexagonal dicarbon antisite defects, respectively. This assignment is based on the comparison of the measured and calculated hyperfine tensors of 13C and 29Si atoms. We investigated the creation and annihilation of this defect as a function of electron-dose and annealing temperature.

scholarly journals High antisite defect concentrations in hard-sphere colloidal Laves phases

Soft Matter ◽  
2020 ◽  
Vol 16 (17) ◽  
pp. 4155-4161 ◽  
Author(s):  
Berend van der Meer ◽  
Frank Smallenburg ◽  
Marjolein Dijkstra ◽  
Laura Filion
Keyword(s):  
Small Particle ◽  
Hard Sphere ◽  
Large Particle ◽  
Antisite Defect ◽  
Laves Phase ◽  
High Concentration ◽  
Laves Phases ◽  
Antisite Defects

We show that the equilibrium Laves phase in binary hard-sphere mixtures contains an extraordinarily high concentration of antisite defects:  we find stable regions where up to 2% of the large-particle lattice sites are occupied by a small particle.

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