A new type of defect structure in 124-superconducting oxide revealed by HREM

1991 ◽  
Vol 49 ◽  
pp. 1092-1093
Author(s):  
R. Sharma ◽  
B.L. Ramakrishna ◽  
N.N. Thadhani ◽  
D. Hianes ◽  
Z. Iqbal
Keyword(s):  
Shock Wave ◽  
Defect Structure ◽  
Neutron Radiation ◽  
Weak Links ◽  
Defect Structures ◽  
New Materials ◽  
New Type ◽  
Current Densities ◽  
Processing Techniques ◽  
Microstructural Studies

After materials with superconducting temperatures higher than liquid nitrogen have been prepared, more emphasis has been on increasing the current densities (Jc) of high Tc superconductors than finding new materials with higher transition temperatures. Different processing techniques i.e thin films, shock wave processing, neutron radiation etc. have been applied in order to increase Jc. Microstructural studies of compounds thus prepared have shown either a decrease in gram boundaries that act as weak-links or increase in defect structure that act as flux-pinning centers. We have studied shock wave synthesized Tl-Ba-Cu-O and shock wave processed Y-123 superconductors with somewhat different properties compared to those prepared by solid-state reaction. Here we report the defect structures observed in the shock-processed Y-124 superconductors.

A New-Type of Defect Generation at a 4H-SiC/SiO2 Interface by Oxidation Induced Compressive Strain

2013 ◽  
Vol 740-742 ◽  
pp. 469-472 ◽  
Author(s):  
Kenta Chokawa ◽  
Shigenori Kato ◽  
Katsumasa Kamaiya ◽  
Kenji Shiraishi
Keyword(s):  
Defect Structure ◽  
Density Functional ◽  
Oxidation Process ◽  
Present Report ◽  
Compressive Strain ◽  
Defect Structures ◽  
Forming Process ◽  
Functional Theory ◽  
New Type ◽  
Related Defect

Our message is oxidation process must be minimized as possible. Many carbon-related defect structures are reported in SiC/SiO2 interface. In this paper, we investigated the effect of oxidation to the defect forming by density functional theory (DFT). In the result, we found carbon defect structure that completely different from in the present report. This defect structure has carbon-carbon single bond with no dangling bond. To see the forming process, compressive strain from inserted oxygen atoms induce the rearrangement of structure and cause C-C defect structure. We can know that this structure is formed with energy gain about 3.8eV. And this C-C defect induces trap state under the conduction bottoms.

Magnetic-history-dependent critical currents in granular high-temperature superconductors: Dependence on defect structures and morphology

1989 ◽  
Vol 47 ◽  
pp. 186-187
Author(s):  
Martin P. Maley ◽  
Michael E. McHenry ◽  
Jeffrey O. Willis
Keyword(s):  
High Temperature ◽  
Critical Current ◽  
High Temperature Superconductors ◽  
Critical Currents ◽  
Weak Links ◽  
Small Scale ◽  
Defect Structures ◽  
Flux Lattice ◽  
Superconducting Coherence Length ◽  
Current Densities

Critical current densities, Jc’s, in conventional low temperature superconductors are controlled by defect structures that provide pinning for the magnetic flux lattice. High critical current densities and strong pinning have been observed in single crystals of the new oxide, high temperature superconductors (HTS) and have been ascribed to the presence of twin planes and to stoichiometry variations in the YBCO compound. Neutron irradiation studies have shown that intragranular Jc’s in YBCO can be strongly enhanced by the point defects introduced by irradiation. However, transport Jc’s determined by intergranular current transfer have remained dissappointingly low in bulk ceramic HTS materials. This has suggested a model of strongly superconducting grains separated by “weak links” that behave as Josephson tunnel junctions.The extraordinarily small superconducting coherence length ζo ∼ 10 A° in the HTS make them considerably more sensitive to small scale defects. Grain boundaries that act as pinning centers in conventional superconductors thus become barriers to current flow in the HTS.

Existence of a new type of irregular shock-wave interaction

1988 ◽  
Vol 23 (5) ◽  
pp. 795-797
Author(s):  
M. D. Gerasimov ◽  
A. V. Panasenko ◽  
V. F. Yatsuk
Keyword(s):  
Shock Wave ◽  
Wave Interaction ◽  
Shock Wave Interaction ◽  
New Type

ULTRASONIC IMAGING AND DATA PROCESSING TECHNIQUES FOR SEMICONDUCTOR AND NEW MATERIALS

1989 ◽  
pp. 784-789 ◽  
Author(s):  
T. Nonaka ◽  
Y. Hayakawa ◽  
S. Takeda ◽  
T. Igarashi ◽  
Y. Takishita ◽  
...  
Keyword(s):  
Data Processing ◽  
Ultrasonic Imaging ◽  
New Materials ◽  
Processing Techniques

Advances in Battery Technologies and Markets: Material Science Aspects

1997 ◽  
Vol 496 ◽  
Author(s):  
A. J. Salkind
Keyword(s):  
Materials Science ◽  
Storage Device ◽  
Energy Storage Device ◽  
New Materials ◽  
Power Devices ◽  
Market Segments ◽  
Storage Devices ◽  
Electrochemical Storage ◽  
Processing Techniques ◽  
Battery Industry

AbstractAdvances in materials innovation, availability, processing, and volumetric and gravimetric utilization, have lead to dramatic changes in the technologies and markets for batteries, and other electrochemical storage devices, in recent years. The increased ability to cycle of the new materials and preparations has also resulted in a more dominant proportion of secondary batteries in the market. The growth of the various technology sectors of the battery and energy storage device industry will be compared to the relevant improvements in materials science. The developments needed in materials, composites, and processing techniques is reviewed, in order to match the ongoing changes in electronic circuits, power devices, transportation, and the growth of portable appliances. An analysis of the technical/market segments of the battery industry is presented.

Defect Structures in Neutron Irradiated 6H-SiC Studied by X-Ray Diffraction Line Profile Analysis

2000 ◽  
Vol 640 ◽  
Author(s):  
C. Seitz ◽  
A. Magerl ◽  
R. Hock ◽  
H. Heissenstein ◽  
R. Helbig
Keyword(s):  
Line Profile ◽  
Correlation Length ◽  
Defect Structure ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Diffraction Line Profile

ABSTRACTWe have investigated by x-ray diffraction defect structures in 6H-SiC after neutron irradiation with different fluences and followed by different annealing procedures. An interpretation along a model of Klimanek [1, 4–6] shows, that higher fluences lead to a stronger than linear reduction of the correlation length, whereas higher annealing temperatures correlate with a better recovery of the correlation length. In addition defects of 1st kind created by irradiation are reduced by annealing. We find that annealing changes the character of the defects and it accentuates a defect structure already present in the original samples.

Electron Microscope Characterization of Pulse Annealed Semiconductors

1980 ◽  
Vol 2 ◽  
Author(s):  
A. G. CULLIS
Keyword(s):  
Electron Microscopy ◽  
Defect Structure ◽  
Device Fabrication ◽  
Fabrication Technology ◽  
The Past ◽  
Semiconductor Structures ◽  
Pulse Processing ◽  
Processing Techniques

ABSTRACTThe pulse processing techniques that have assumed prominence over the past few years offer various important advantages for device fabrication technology. However, the usefulness of each individual method depends substantially upon the specific annealing mechanism involved. This article demonstrates the role of electron microscopy in elucidating such mechanisms and in analysing annealed semiconductor structures of importance to both research workers and semiconductor technologists. The range of laser and electron beam pulse annealing methods is covered and defect structure transitions observed are related to the solid and liquid phase processes occurring. Characteristic impurity trapping and segregation phenomena are described.

Research of High-Power Underwater Explosive Based on Analysis of Underwater Energy

2013 ◽  
Vol 848 ◽  
pp. 183-187
Author(s):  
Qiu An Huang ◽  
Geng Guang Xu ◽  
Yong Jiang Wei ◽  
Xue Mei Liu
Keyword(s):  
Shock Wave ◽  
High Power ◽  
Energy Output ◽  
Underwater Shock Wave ◽  
Tnt Equivalent ◽  
Shock Wave Energy ◽  
Output Structure ◽  
Main Charge ◽  
New Type ◽  
Underwater Shock

In this paper,by researching the underwater energy output structure of explosion and improving the technical method to enhance the energy of underwater high-power explosive,a new type of underwater high-power PBX explosive was developed. This type of PBX,of which the underwater shock wave energy was 1.75 TNT equivalent and its bubble energy was 2.41 TNT equivalent,was suitable for the main charge of underwater weapon warhead and its energy archived the domestic leading level.

The Reproduction of New Clothing Materials - Lotus Effect

2014 ◽  
Vol 1055 ◽  
pp. 88-91
Author(s):  
Xian Yuan Wei
Keyword(s):  
New Materials ◽  
Modern Life ◽  
Lotus Effect ◽  
Clothing Design ◽  
Textile Fabrics ◽  
Innovative Method ◽  
New Type

In modern life, textile fabrics are widely used. When using a great variety of new type fabrics, the reproduction of new materials is frequently treated as an innovative method. The redesign of fabrics has injected boundless vitality and vigor into clothing design. The lotus fiber, as a novel kind of fiber, has brought great pleasant to our lives.

Transport Measurements on Superconducting YBa2Cu3O7-δ Thin Film Lines

1989 ◽  
Vol 169 ◽  
Author(s):  
B. H. Moeckly ◽  
D. K. Lathrop ◽  
G. F. Redinbo ◽  
S. E. Russek ◽  
R. A. Buhrman
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Critical Current ◽  
Weak Link ◽  
High Sensitivity ◽  
Weak Links ◽  
Microwave Response ◽  
Field Response ◽  
Current Densities ◽  
Iv Curves

AbstractCritical current densities, magnetic field response, and microwave response have been measured for laser ablated YBa2Cu3O7-δ thin film lines on MgO and SrTiO3 substrates. Films on SrTiO3 have critical current densities > 1 x 106 A/cm2 at 77K and show uniform transport properties in lines of all sizes. Films on MgO have critical current densities which range between 102 and 106 A/cm2 at 77K and show considerable variation from device to device on the same chip. Narrow lines on MgO with low critical current densities show Josephson weak link structure which includes RSJ-like IV curves, microwave induced constant voltage steps, and a high sensitivity to magnetic field. The presence of the Josephson weak links is correlated with small amounts of misaligned grains in films on MgO.

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