Degree of Permanent Densification in Oxide Glasses upon Extreme Compression up to 24 GPa at Room Temperature

2020 ◽  
Vol 11 (8) ◽  
pp. 2917-2924 ◽  
Author(s):  
Sung Keun Lee ◽  
Kwan Young Mun ◽  
Yong-Hyun Kim ◽  
Juho Lhee ◽  
Takuo Okuchi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Oxide Glasses ◽  
Permanent Densification

scholarly journals Highly ductile amorphous oxide at room temperature and high strain rate

Science ◽  
2019 ◽  
Vol 366 (6467) ◽  
pp. 864-869 ◽  
Author(s):  
Erkka J. Frankberg ◽  
Janne Kalikka ◽  
Francisco García Ferré ◽  
Lucile Joly-Pottuz ◽  
Turkka Salminen ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Room Temperature ◽  
High Strain ◽  
Total Elongation ◽  
Modern World ◽  
Mechanical Resistance ◽  
Oxide Glasses ◽  
Amorphous Oxide ◽  
Damage Tolerant

Oxide glasses are an integral part of the modern world, but their usefulness can be limited by their characteristic brittleness at room temperature. We show that amorphous aluminum oxide can permanently deform without fracture at room temperature and high strain rate by a viscous creep mechanism. These thin-films can reach flow stress at room temperature and can flow plastically up to a total elongation of 100%, provided that the material is dense and free of geometrical flaws. Our study demonstrates a much higher ductility for an amorphous oxide at low temperature than previous observations. This discovery may facilitate the realization of damage-tolerant glass materials that contribute in new ways, with the potential to improve the mechanical resistance and reliability of applications such as electronic devices and batteries.

Electrical conduction in composites of nanosized iron particles and oxide glasses

1994 ◽  
Vol 9 (9) ◽  
pp. 2314-2318 ◽  
Author(s):  
S. Roy ◽  
D. Chakravorty
Keyword(s):  
Temperature Region ◽  
Glass Matrix ◽  
Room Temperature ◽  
Electron Tunneling ◽  
Metal Particles ◽  
Oxide Glasses ◽  
Iron Particles ◽  
Average Value ◽  
Tunneling Mechanism ◽  
Nanosized Iron

Nanocomposites involving iron particles in silica glass matrix have been synthesized by the hot pressing of suitably reduced precursor gel powders. The metal particles have diameters in the range 3.8 to 10.2 nm. An almost four orders of magnitude resistivity range at room temperature has been obtained by such changes in particle diameters. The resistivity in the temperature range 200-340 K shows a fractional temperature dependence with an average value of n ∼ 0.69. The resistivity changes in this temperature region can be explained on the basis of an electron tunneling mechanism.

Room-temperature persistent hole burning of Sm^2+ in oxide glasses

1993 ◽  
Vol 18 (19) ◽  
pp. 1586 ◽  
Author(s):  
K. Hirao ◽  
S. Todoroki ◽  
D. H. Cho ◽  
N. Soga
Keyword(s):  
Room Temperature ◽  
Hole Burning ◽  
Oxide Glasses

Dependence of Intergranular Fracture on Boundary Topography and Cohesion

1973 ◽  
Vol 31 ◽  
pp. 150-151
Author(s):  
J. E. Doherty ◽  
A. F. Giamei ◽  
B. H. Kear ◽  
C. W. Steinke
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Nickel Base Superalloy ◽  
Boundary Shear ◽  
Room Temperature Ductility ◽  
Solid Solution Matrix ◽  
Nickel Base ◽  
Solution Matrix ◽  
Different Levels ◽  
Base Superalloy

Recently we have been investigating a class of nickel-base superalloys which possess substantial room temperature ductility. This improvement in ductility is directly related to improvements in grain boundary strength due to increased boundary cohesion through control of detrimental impurities and improved boundary shear strength by controlled grain boundary micros true tures.For these investigations an experimental nickel-base superalloy was doped with different levels of sulphur impurity. The micros tructure after a heat treatment of 1360°C for 2 hr, 1200°C for 16 hr consists of coherent precipitates of γ’ Ni3(Al,X) in a nickel solid solution matrix.

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

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