Simulation of Alkali Migration in β′′-Alumina Under Ion Bombardment

1995 ◽  
Vol 389 ◽  
Author(s):  
Paulo C.T. D’Ajello ◽  
André A. Pasa
Keyword(s):  
Theoretical Model ◽  
Electric Field ◽  
Ion Implantation ◽  
Room Temperature ◽  
Ion Bombardment ◽  
Ionic Mobility ◽  
Ionic Conductor ◽  
Ionization Process ◽  
Practical Applications ◽  
Dielectric Solids

ABSTRACTAmong the different effects induced by ion implantation into dielectric solids, the enhancement of the ionic mobility is the most important regarding practical applications. We simulated the Na migration in a super-ionic conductor, sodium β″-alumina, irradiated with Ar (E=200 keV) at room temperature. A theoretical model to describe the electric field originated in the bombarded region near the surface was developed. The model emphasizes the relation between the electric field and the energy deposited by the ions in the ionization process.

Low Rons in 3kV 4H-SiC UMOSFET with MeV Implanted Buried P-Base Region

2015 ◽  
Vol 821-823 ◽  
pp. 769-772 ◽  
Author(s):  
Shinsuke Harada ◽  
Makoto Kato ◽  
Megumi Shinozaki ◽  
Yusuke Kobayashi ◽  
Keiko Ariyoshi ◽  
...  
Keyword(s):  
Electric Field ◽  
Ion Implantation ◽  
Threshold Voltage ◽  
Room Temperature ◽  
Gate Oxide ◽  
Structural Parameter ◽  
Base Region ◽  
Cell Geometry ◽  
Hexagonal Cell ◽  
Channel Density

3kV UMOSFET with buried p-base regions was developed to realize the low on-resistance with low electric field in the gate oxide for off-state. The buried p-base region was formed simultaneously with the p-base region by utilizing MeV ion implantation. Influence by the structural parameter such as cell geometry and space between the buried p-base region and the trench gate was investigated. The hexagonal cell with high channel density exhibits an extremely low on-resistance of 6.8 mΩcm2 with threshold voltage of 5.0 V at room temperature.

Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

1988 ◽  
Vol 46 ◽  
pp. 880-881
Author(s):  
Bradley L. Thiel ◽  
Chan Han R. P. ◽  
Kurosky L. C. Hutter ◽  
I. A. Aksay ◽  
Mehmet Sarikaya
Keyword(s):  
Grain Boundary ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Boundary Phase ◽  
Spectroscopic Techniques ◽  
Transition Width ◽  
Practical Applications ◽  
Thin Foils ◽  
Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

ALCHEMI of B2-Ordered Fe50Al45Me5 alloys

1996 ◽  
Vol 54 ◽  
pp. 548-549
Author(s):  
Ian M. Anderson
Keyword(s):  
Room Temperature ◽  
Iron Aluminide ◽  
Low Density ◽  
Intermetallic Alloys ◽  
Practical Applications ◽  
Alloying Additions ◽  
Site Distribution ◽  
Good Corrosion Resistance ◽  
Room Temperature Ductility ◽  
The Matrix

B2-ordered iron aluminide intermetallic alloys exhibit a combination of attractive properties such as low density and good corrosion resistance. However, the practical applications of these alloys are limited by their poor fracture toughness and low room temperature ductility. One current strategy for overcoming these undesirable properties is to attempt to modify the basic chemistry of the materials with alloying additions. These changes in the chemistry of the material cannot be fully understood without a knowledge of the site-distribution of the alloying elements. In this paper, the site-distributions of a series of 3d-transition metal alloying additions in B2-ordered iron aluminides are studied with ALCHEMI.A series of seven alloys of stoichiometry Fe50AL45Me5, with Me = {Ti, V, Cr, Mn, Co, Ni, Cu}, were prepared with identical heating cycles. Microalloying additions of 0.2% B and 0.1% Zr were also incorporated to strengthen the grain boundaries, but these alloying additions have little influence on the matrix chemistry and are incidental to this study.

scholarly journals Electrically driven formation and dynamics of Pac-Man solitons in smectic A liquid crystals

2021 ◽  
Author(s):  
Yuan Shen ◽  
Ingo Dierking
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Spatiotemporal Chaos ◽  
Practical Applications ◽  
Smectic A ◽  
Fundamental Science ◽  
Smectic A Liquid Crystals

Electric field driven instabilities of liquid crystals, such as electro-convections, spatiotemporal chaos, backflows, and solitons are of great importance for both fundamental science and practical applications. Here we demonstrate that...

Non-adhesive lotus and other hydrophobic materials

2008 ◽  
Vol 366 (1870) ◽  
pp. 1539-1556 ◽  
Author(s):  
David Quéré ◽  
Mathilde Reyssat
Keyword(s):  
Solid Surface ◽  
Room Temperature ◽  
Water Repellency ◽  
Short Review ◽  
Water Repellent ◽  
Practical Applications ◽  
Hydrophobic Materials ◽  
Volatile Liquid ◽  
Air Cushion ◽  
The Stability

Superhydrophobic materials recently attracted a lot of attention, owing to the potential practical applications of such surfaces—they literally repel water, which hardly sticks to them, bounces off after an impact and slips on them. In this short review, we describe how water repellency arises from the presence of hydrophobic microstructures at the solid surface. A drop deposited on such a substrate can float above the textures, mimicking at room temperature what happens on very hot plates; then, a vapour layer comes between the solid and the volatile liquid, as described long ago by Leidenfrost. We present several examples of superhydrophobic materials (either natural or synthetic), and stress more particularly the stability of the air cushion—the liquid could also penetrate the textures, inducing a very different wetting state, much more sticky, due to the possibility of pinning on the numerous defects. This description allows us to discuss (in quite a preliminary way) the optimal design to be given to a solid surface to make it robustly water repellent.

A New Hafnium-Beryllium System Prioduced by Ion Implantation and Annealing Techniques

1983 ◽  
Vol 27 ◽  
Author(s):  
J.C. Soares ◽  
A.A. Melo ◽  
M.F. DA Silva ◽  
E.J. Alves ◽  
K. Freitag ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Low Dose ◽  
Correlation Method ◽  
High Dose ◽  
Tetrahedral Sites ◽  
Time Differential ◽  
Before And After ◽  
Beryllium Foil

ABSTRACTLow and high dose hafnium imolanted beryllium samoles have been prepared at room temperature by ion implantation of beryllium commercial foils and single crystals. These samples have been studied before and after annealing with the time differential perturbed angular correlation method (TDPAC) and with Rutherford backscattering and channeling techniques. A new metastable system has been discovered in TDPAC-measurements in a low dose hafnium implanted beryllium foil annealed at 500°C. Channeling measurements show that the hafnium atoms after annealing, are in the regular tetrahedral sites but dislocated from the previous position occupied after implantation. The formation of this system is connected with the redistribution of oxygen in a thin layer under the surface. This effect does not take place precisely at the same temperature in foils and in single crystals.

scholarly journals Electric Field Dependence of the Fluorescence Intensity of Solute Molecules and Fourth Order Effects

1985 ◽  
Vol 40 (9) ◽  
pp. 874-876
Author(s):  
Hilmar Bischof ◽  
Wolfram Baumann
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Field Dependence ◽  
Fourth Order ◽  
Fluorescence Intensity ◽  
Room Temperature ◽  
Order Effects ◽  
Electric Field Dependence ◽  
Total Fluorescence

Abstract The effect of an external electric field on the total fluorescence of solute molecules is studied up to fourth order theoretically, and is checked experimentally with 4´-N,N-dimethylamino- 4-nitrostilbene in dioxane at room temperature.

Generation of Defects and Strain by Ion Implantation in Ge (100) Single Crystals, and in Pseudomorphic GexSi1-x Films Grown on Si (100)

1992 ◽  
Vol 262 ◽  
Author(s):  
D. Y. C. Lie ◽  
A. Vantomme ◽  
F. Eisen ◽  
M. -A. Nicolet ◽  
V. Arbet-Engels ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Room Temperature ◽  
Defect Concentration ◽  
Double Crystal ◽  
X Ray ◽  
Positive Strain ◽  
Independent Coefficient ◽  
The Relationship ◽  
Si Ion Implantation

ABSTRACTWe have studied the damage and strain produced in Ge (100) single crystals by implantation of various doses of 300 keV 28Si ions at room temperature. The analyzing tools were x-ray double-crystal diffractometry, and MeV 4He channeling spectrometry. The damage induced by implantation produces positive strain in Ge (100). The maximum perpendicular strain and maximum defect concentration rise nonlinearly with increasing dose. These quantities are linearly related with a dose-independent coefficient of ∼ 0.013 for Ge (100) single crystals implanted at room temperature. The results are compared with those available for Si (100) self-implantation. We have also monitored the strain and defects generated in pseudomorphic Ge0.1Si0.9/Si (100) films induced by room temperature 28Si ion implantation. It is found that the relationship between the strain and defect concentration induced by ion implantation is no longer a simple linear one.

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