scholarly journals Room‐temperature dislocation plasticity in SrTiO 3 tuned by defect chemistry

2021 ◽  
Author(s):  
Stephan Stich ◽  
Kuan Ding ◽  
Qaisar Khushi Muhammad ◽  
Lukas Porz ◽  
Christian Minnert ◽  
...  
Keyword(s):  
Room Temperature ◽  
Defect Chemistry ◽  
Dislocation Plasticity

scholarly journals Crystalline Structure, Defect Chemistry and Room Temperature Colossal Permittivity of Nd-doped Barium Titanate

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Qiaomei Sun ◽  
Qilin Gu ◽  
Kongjun Zhu ◽  
Rongying Jin ◽  
Jinsong Liu ◽  
...  
Keyword(s):  
Barium Titanate ◽  
Crystalline Structure ◽  
Room Temperature ◽  
Defect Chemistry ◽  
Structure Defect ◽  
Colossal Permittivity ◽  
Doped Barium Titanate

Dislocation Plasticity and Complementary Deformation Mechanisms in Polycrystalline Mg Alloys

2004 ◽  
Vol 449-452 ◽  
pp. 665-668 ◽  
Author(s):  
Junichi Koike
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Deformation Mechanism ◽  
Room Temperature ◽  
Grain Boundary Sliding ◽  
Mg Alloys ◽  
Deformation Mechanisms ◽  
Slip Systems ◽  
Dislocation Plasticity ◽  
Boundary Sliding

Deformation mechanisms of Mg-Al-Zn (AZ31) alloys were investigated by performing tensile test at room temperature. In fine grain Mg alloys deformed at room temperature, nonbasal slip systems were found to be active as well as basal slip systems because of grain-boundary compatibility effect. Slip-induced grain-boundary sliding occurred as a complementary deformation mechanism to give rise to c-axis component of strain. With increasing grain size, the activation of the nonbasal slip systems was limited near grain boundaries. Instead of grain-boundary sliding, twinning occurred as a complementary deformation mechanism in large grained samples. Orientation analysis of twins indicated that twinning is induced by stress concentration due to the pile up of basal dislocations. The grain-size dependence on deformation mechanism was found to affect yielding behavior both microscopically and macroscopically which can influence various mechanical properties such as fatigue and creep.

scholarly journals Direct Observation of Room-Temperature Dislocation Plasticity in Diamond

Matter ◽  
2020 ◽  
Vol 2 (5) ◽  
pp. 1222-1232 ◽  
Author(s):  
Anmin Nie ◽  
Yeqiang Bu ◽  
Junquan Huang ◽  
Yecheng Shao ◽  
Yizhi Zhang ◽  
...  
Keyword(s):  
Direct Observation ◽  
Room Temperature ◽  
Dislocation Plasticity

scholarly journals Bridging the Gap between Bulk Compression and Indentation Test on Room-Temperature Plasticity in Oxides: Case Study on SrTiO3

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 933 ◽  
Author(s):  
Xufei Fang ◽  
Lukas Porz ◽  
Kuan Ding ◽  
Atsutomo Nakamura
Keyword(s):  
Room Temperature ◽  
Indentation Test ◽  
Ceramic Materials ◽  
Semiconducting Materials ◽  
The Road ◽  
Dislocation Plasticity ◽  
Dislocation Behavior ◽  
Testing Protocols ◽  
Functional Ceramics

Dislocation-based functionalities in inorganic ceramics and semiconductors are drawing increasing attention, contrasting the conventional belief that the majority of ceramic materials are brittle at room temperature. Understanding the dislocation behavior in ceramics and advanced semiconducting materials is therefore critical for the mechanical reliability of such materials and devices designed for harvesting the dislocation-based functionalities. Here we compare the mechanical testing between indentation at nano-/microscale and bulk uniaxial deformation at macroscale and highlight the dislocation plasticity in single crystal SrTiO3, a model perovskite. The similarities and differences as well as the advantages and limitations of both testing protocols are discussed based on the experimental outcome of the crystal plasticity, with a focus on the pre-existing defect population being probed with different volumes across the length scales (“size effect”). We expect this work to pave the road for studying dislocation-based plasticity in various advanced functional ceramics and semiconductors.

Room temperature dislocation plasticity in silicon

2005 ◽  
Vol 85 (2-3) ◽  
pp. 323-330 ◽  
Author(s):  
A.M. Minor § ◽  
E.T. Lilleodden ◽  
M. Jin ◽  
E.A. Stach ◽  
D.C. Chrzan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Dislocation Plasticity

Sintering kinetics, defect chemistry and room-temperature mechanical properties of titanium nitride prepared by spark plasma sintering

2019 ◽  
Vol 807 ◽  
pp. 151666 ◽  
Author(s):  
J.M. Morgado Chávez ◽  
B.M. Moshtaghioun ◽  
F.L. Cumbrera Hernández ◽  
D. Gómez García
Keyword(s):  
Mechanical Properties ◽  
Titanium Nitride ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Defect Chemistry ◽  
Sintering Kinetics ◽  
Plasma Sintering ◽  
Spark Plasma

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).

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