scholarly journals Lattice hardening due to vacancy diffusion in (GeTe)mSb2Te3 alloys

2019 ◽  
Vol 126 (5) ◽  
pp. 055106 ◽  
Author(s):  
Wanyue Peng ◽  
David M. Smiadak ◽  
Michael G. Boehlert ◽  
Spencer Mather ◽  
Jared B. Williams ◽  
...  
Keyword(s):  
Vacancy Diffusion ◽  
Lattice Hardening

Numerical Methods for Analysis of Charged Vacancy Diffusion in Dielectric Solids

2006 ◽  
Author(s):  
John D. Clayton ◽  
Peter W. Chung ◽  
Michael A. Greenfield ◽  
WIlliam D. Nothwang
Keyword(s):  
Numerical Methods ◽  
Vacancy Diffusion ◽  
Dielectric Solids

Statistical study of vacancy diffusion in TiC and TaC

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Xiaochuan Tang ◽  
Rofiques Salehin ◽  
Gregory B. Thompson ◽  
Christopher R. Weinberger
Keyword(s):  
Statistical Study ◽  
Vacancy Diffusion

Microstructural dependence of vacancy diffusion in ordered alloys

1994 ◽  
Vol 75 (3) ◽  
pp. 1467-1472 ◽  
Author(s):  
T. F. Lindsey ◽  
B. Fultz
Keyword(s):  
Vacancy Diffusion ◽  
Ordered Alloys

Isotope effect in vacancy diffusion

1959 ◽  
Vol 4 (44) ◽  
pp. 899-906 ◽  
Author(s):  
K. Tharmalingam ◽  
A. B. Lidiard
Keyword(s):  
Isotope Effect ◽  
Vacancy Diffusion

Co2Si, CrSi2, ZrSi2 and TiSi2 Formation Studied by a Radioactive 31Si Marker Technique

1981 ◽  
Vol 10 ◽  
Author(s):  
A. P. Botha ◽  
R. Pretorius
Keyword(s):  
Diffusion Coefficient ◽  
Half Life ◽  
Vacancy Diffusion ◽  
Silicide Formation ◽  
Activity Profile ◽  
Initial Layer ◽  
Self Diffusion ◽  
Silicide Layer ◽  
Self Diffusion Coefficient

Radioactive 31Si (half-life, 2.62 h) was used as a marker to study Co2Si, CrSi2, TiSi2 and ZrSi2 formation. By marking the initial layer of silicide with radioactive silicon atoms and by measuring the activity profile in the silicide layer after further silicide formation, the dominant diffusing species and its mechanism of diffusion during the formation of these silicides could be determined. For Co2Si it was found that cobalt is the diffusing species, while disilicide formation was found to take place by silicon substitutional (vacancy) diffusion, with a high self-diffusion coefficient.

Point Defect Properties from Metal Diffusion Experiments — What Does the Data Really Tell Us?

1997 ◽  
Vol 469 ◽  
Author(s):  
Srinivasan Chakravarthit ◽  
Scott T. Dunham
Keyword(s):  
Point Defect ◽  
Equilibrium Concentration ◽  
Simulation Software ◽  
Published Data ◽  
Vacancy Diffusion ◽  
Metal Diffusion ◽  
Float Zone ◽  
Equilibrium Concentrations ◽  
Parameter Values ◽  
Carbon Concentrations

Point defect properties, including diffusivities and equilibrium concentrations for both interstitials and vacancies, are commonly extracted from metal diffusion experiments, and these values are widely used in process simulation software. However, in many cases, these parameter values were extracted using oversimplified models which ignore interactions between interstitial and vacancy diffusion mechanisms. Questions about the accuracy of these parameters have come from ab-initio defect calculations which conclude that vacancies diffuse faster than interstitials, in contrast with published reports on metal diffusion which find vacancies diffuse much more slowly than interstitials. We have reanalyzed published data for zinc and platinum diffusion and find that it is possible to match all of the data using fast vacancy diffusivity. The most direct evidence for slow vacancy diffusion (and a high equilibrium concentration) comes from platinum diffusion experiments. However, we are able to reproduce these results with fast V diffusion and carbon/interstitial clustering, using carbon concentrations typical of Czochralski and float zone silicon (1016cm−3). We evaluate the effectiveness of metal diffusion experiments in determining point defect parameters, and find that it is not possible to reliably determine both diffusivities and equilibrium concentrations for both interstitials and vacancies from metal diffusion results.

Rational Design of Organic Electro-Optic Materials

2001 ◽  
Vol 708 ◽  
Author(s):  
Alex Jen ◽  
Robert Neilsen ◽  
Bruce Robinson ◽  
William H. Steier ◽  
Larry Dalton
Keyword(s):  
Wavelength Division Multiplexing ◽  
Material Properties ◽  
Electrostatic Interactions ◽  
Rational Design ◽  
Elevated Temperatures ◽  
Optical Loss ◽  
Quality Factors ◽  
Electro Optic ◽  
Lattice Hardening

ABSTRACTA number of material properties must be optimized before organic electro-optic materials can be used for practical device applications. These include electro-optic activity, optical transparency, and stability including both thermal and photochemical stability. Exploiting an improved understanding of the structure/function relationships, we have recently prepared materials exhibiting electro-optic coefficients of greater than 50 pm/V and optical loss values of less than 0.7 dB/cm at the telecommunication wavelengths of 1.3 and 1.55 microns. When oxygen is excluded to a reasonable extent, long-term photostability to optical power levels of 20 mW has been observed. Photostability is further improved by addition of scavengers and by lattice hardening. Long-term (greater than 1000 hours) thermal stability of poling-induced electro-optic activity is also observed at elevated temperatures (greater than 80°C) when appropriate lattice hardening is used. The successful improvement of organic electro-optic materials rests upon (1) attention to the design of chromophore structure including design to inhibit unwanted intermolecular electrostatic interactions and to improve chromophore instability and (2) attention to processing conditions including those involved in spin casting, electric field poling, and lattice hardening. A particularly attractive new direction has been the exploitation of dendrimer structures and particularly of multi-chromophore containing dendrimer structures. This approach has permitted the simultaneous improvement of all material properties. Development of new materials has facilitated the fabrication of a number of prototype devices and most recently has permitted investigation of the incorporation of electro-optic materials into photonic bandgap and microresonator structures. The latter are relevant to active wavelength division multiplexing (WDM). Significant quality factors (greater than 10,000) have been realized for such devices permitting wavelength discrimination at telecommunication wavelengths of 0.01 nm.

Red-shift in the InGaAsP/GaInP active region using impurity free vacancy diffusion induced quantum well intermixing

2015 ◽  
Vol 644 ◽  
pp. 398-403 ◽  
Author(s):  
Tao Lin ◽  
Haoqing Zhang ◽  
Ruijuan Sun ◽  
Yupeng Duan ◽  
Nan Lin ◽  
...  
Keyword(s):  
Active Region ◽  
Quantum Well ◽  
Red Shift ◽  
Vacancy Diffusion ◽  
Quantum Well Intermixing ◽  
Free Vacancy
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