Achieving large uniform tensile elasticity in microfabricated diamond

Science ◽  
2020 ◽  
Vol 371 (6524) ◽  
pp. 76-78
Author(s):  
Chaoqun Dang ◽  
Jyh-Pin Chou ◽  
Bing Dai ◽  
Chang-Ti Chou ◽  
Yang Yang ◽  
...  
Keyword(s):  
Information Technologies ◽  
Room Temperature ◽  
Strain Engineering ◽  
Uniaxial Tensile ◽  
Figures Of Merit ◽  
Bridge Structures ◽  
Device Applications ◽  
Application Potential ◽  
Bulk Band ◽  
Elastic Strains

Diamond is not only the hardest material in nature, but is also an extreme electronic material with an ultrawide bandgap, exceptional carrier mobilities, and thermal conductivity. Straining diamond can push such extreme figures of merit for device applications. We microfabricated single-crystalline diamond bridge structures with ~1 micrometer length by ~100 nanometer width and achieved sample-wide uniform elastic strains under uniaxial tensile loading along the [100], [101], and [111] directions at room temperature. We also demonstrated deep elastic straining of diamond microbridge arrays. The ultralarge, highly controllable elastic strains can fundamentally change the bulk band structures of diamond, including a substantial calculated bandgap reduction as much as ~2 electron volts. Our demonstration highlights the immense application potential of deep elastic strain engineering for photonics, electronics, and quantum information technologies.

scholarly journals Numerical Analysis of the Perforated Steel Sheets Under Uni-Axial Tensile Force

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 632 ◽  
Author(s):  
Ahmed M. Sayed
Keyword(s):  
Load Capacity ◽  
Tensile Force ◽  
Three Dimensional ◽  
Tensile Load ◽  
Experimental Tests ◽  
Strain Engineering ◽  
Uniaxial Tensile ◽  
Fe Model ◽  
Stress Strain ◽  
Steel Sheets

The perforated steel sheets have many uses, so they should be studied under the influence of the uniaxial tensile load. The presence of these holes in the steel sheets certainly affects the mechanical properties. This paper aims at studying the behavior of the stress-strain engineering relationships of the perforated steel sheets. To achieve this, the three-dimensional finite element (FE) model is mainly designed to investigate the effect of this condition. Experimental tests were carried out on solid specimens to be used in the test of model accuracy of the FE simulation. Simulation testing shows that the FE modeling revealed the ability to calculate the stress-strain engineering relationships of perforated steel sheets. It can be concluded that the effect of a perforated rhombus shape is greater than the others, and perforated square shape has no effect on the stress-strain engineering relationships. The efficiency of the perforated staggered or linearly distribution shapes with the actual net area on the applied loads has the opposite effect, as it reduces the load capacity for all types of perforated shapes. Despite the decrease in load capacity, it improves the properties of the steel sheets.

scholarly journals Observation of strong excitonic magneto-chiral anisotropy in twisted bilayer van der Waals crystals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shoufeng Lan ◽  
Xiaoze Liu ◽  
Siqi Wang ◽  
Hanyu Zhu ◽  
Yawen Liu ◽  
...  
Keyword(s):  
Time Reversal ◽  
Room Temperature ◽  
Photochemical Reactions ◽  
Full Width ◽  
Half Maximum ◽  
A Value ◽  
Device Applications ◽  
Spectral Splitting ◽  
Iron Garnet ◽  
Spontaneous Magnetic Moment

AbstractThe interplay between chirality and magnetism generates a distinct physical process, the magneto-chiral effect, which enables one to develop functionalities that cannot be achieved solely by any of the two. Such a process is universal with the breaking of parity-inversion and time-reversal symmetry simultaneously. However, the magneto-chiral effect observed so far is weak when the matter responds to photons, electrons, or phonons. Here we report the first observation of strong magneto-chiral response to excitons in a twisted bilayer tungsten disulfide with the amplitude of excitonic magneto-chiral (ExMCh) anisotropy reaches a value of ~4%. We further found the ExMCh anisotropy features with a spectral splitting of ~7 nm, precisely the full-width at half maximum of the excitonic chirality spectrum. Without an externally applied strong magnetic field, the observed ExMCh effect with a spontaneous magnetic moment from the ferromagnetic substrate of thulium iron garnet at room temperature is favorable for device applications. The unique ExMCh processes provide a new pathway to actively control magneto-chiral applications in photochemical reactions, asymmetric synthesis, and drug delivery.

Room-Temperature Luminescence of a Variety of Compounds on 1% α-Cyclodextrin/NaCl Mixture

1989 ◽  
Vol 43 (5) ◽  
pp. 810-812 ◽  
Author(s):  
Marsha D. Richmond ◽  
Robert J. Hurtubise
Keyword(s):  
Solid Surface ◽  
Room Temperature ◽  
Lower Cost ◽  
Model Compounds ◽  
Figures Of Merit ◽  
Room Temperature Luminescence ◽  
Analytical Figures Of Merit

With the use of model compounds of widely different functionality, it was found that a 1% α-cyclodextrin/NaCl mixture could be used in place of an 80% α-cyclodextrin/NaCl mixture to obtain solid surface room-temperature fluorescence (RTF) and phosphorescence (RTP) data. Analytical figures of merit are reported for four compounds. The use of a smaller percentage of α-cyclodextrin results in lower cost; no loss of analytical integrity, compared with that for an 80% α-cyclodextrin/NaCl mixture; and easier handling of the α-cyclodextrin/NaCl mixtures.

scholarly journals Serial femtosecond and serial synchrotron crystallography yield data of equivalent quality: a systematic comparison

2020 ◽  
Author(s):  
P. Mehrabi ◽  
R. Bücker ◽  
G. Bourenkov ◽  
H.M. Ginn ◽  
D. von Stetten ◽  
...  
Keyword(s):  
Radiation Source ◽  
Room Temperature ◽  
Delivery Device ◽  
Analysis Software ◽  
Yield Data ◽  
Time Resolved ◽  
Systematic Comparison ◽  
Figures Of Merit ◽  
Radiation Sources ◽  
Data Statistics

AbstractFor the two proteins myoglobin (MB) and fluoroacetate dehalogenase (FAcD), we present a systematic comparison of crystallographic diffraction data collected by serial femtosecond (SFX) and serial synchrotron crystallography (SSX). To maximize comparability, we used the same batch of crystals, the same sample delivery device, as well as the same data analysis software. Overall figures of merit indicate that the data of both radiation sources are of equivalent quality. For both proteins reasonable data statistics can be obtained with approximately 5000 room temperature diffraction images irrespective of the radiation source. The direct comparability of SSX and SFX data indicates that diffraction quality is rather linked to the properties of the crystals than to the radiation source. Time-resolved experiments can therefore be conducted at the source that best matches the desired time-resolution.

Influence of Curing Temperature on Metakaolin-Based Geopolymers

2014 ◽  
Vol 775-776 ◽  
pp. 210-215
Author(s):  
Danúbia Lisbôa da Costa ◽  
Romualdo Rodrigues Menezes ◽  
Gelmires Araújo Neves ◽  
Sandro Marden Torres
Keyword(s):  
Room Temperature ◽  
Industrial Wastes ◽  
Curing Temperature ◽  
Inorganic Polymers ◽  
Flexural Test ◽  
X Ray Diffraction ◽  
Curing Conditions ◽  
X Ray ◽  
Natural Minerals ◽  
Application Potential

Geopolymers, also known as inorganic polymers, are aluminosilicates with cementing characteristics that have great application potential. They are produced by the alkaline activation of aluminosilicates precursors such as industrial wastes, calcined clays, natural minerals, among others and have their properties intimately associated to characteristics of the precursor materials and curing conditions. In this sense, this study aims to evaluate the mechanical behavior of geopolymers obtained from metakaolin according to the curing temperature. The geopolymerization was reached by the mixture of metakaolin with NaOH and the curing of the specimens was held at room temperature, 60°C and 100°C. The specimens were characterized by X-ray diffraction, mercury intrusion porosimetry, and SEM. The mechanical strength was determined by flexural test. The results show that the process of geopolymerization suffers a direct influence of the curing temperature used.

Thin-film thermoelectric devices with high room-temperature figures of merit

2010 ◽  
pp. 120-125 ◽  
Author(s):  
Rama Venkatasubramanian ◽  
Edward Silvola ◽  
Thomas Colpitts ◽  
Brooks O'Quinn
Keyword(s):  
Thin Film ◽  
Room Temperature ◽  
Thermoelectric Devices ◽  
Figures Of Merit

Tensile Properties at High and Low Temperatures and at Room Temperature after High-Temperature Exposure

2004 ◽  
pp. 211-242
Keyword(s):  
High Temperatures ◽  
Room Temperature ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Data Set ◽  
Casting Alloys ◽  
Subzero Temperatures ◽  
Wide Range ◽  
Temperature Exposure ◽  
High And Low Temperatures

Abstract This data set contains the results of uniaxial tensile tests of a wide range of aluminum casting alloys conducted at high temperatures from 100 to 370 deg C, subzero temperatures from -269 to -28 deg C, and room temperature after holding at high temperatures from 100 to 370 deg C. In most cases, tests were made of several lots of material of each alloy and temper. The results for the several lots were then analyzed together graphically and statistically, and the averages were normalized to the room-temperature typical values. For some alloys, "representative" values (raw data) rather than typical values are provided.

Effect of Fast Annealing on Microstructure and Mechanical Properties of Non-Oriented Al-Si Low C Electrical Steels

2007 ◽  
Vol 560 ◽  
pp. 29-34 ◽  
Author(s):  
Emmanuel Gutiérrez C. ◽  
Armando Salinas-Rodríguez ◽  
Enrique Nava-Vázquez
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Room Temperature ◽  
Tensile Tests ◽  
Rate Of Change ◽  
Uniaxial Tensile ◽  
Electrical Steels ◽  
Offset Yield Strength ◽  
Microstructure And Mechanical Properties ◽  
Increasing Temperature

The effects of heating rate and annealing temperature on the microstructure and mechanical properties of cold rolled Al-Si, low C non-oriented electrical steels are investigated using SEM metallography and uniaxial tensile tests. The experimental results show that short term annealing at temperatures up to 850 °C result in microstructures consisting of recrystallized ferrite grains with sizes similar to those observed in industrial semi-processed strips subjected to long term batch annealing treatments. Within the temperature range investigated, the grain size increases and the 0.2% offset yield strength decreases with increasing temperature. It was observed that the rate of change of grain size with increasing temperature increases when annealing is performed at temperatures greater than Ac1 (~870 °C). This effect is attributed to Fe3C dissolution and rapid C segregation to austenite for annealing temperatures within the ferrite+austenite phase field. This leads to faster ferrite growth and formation of pearlite when the steel is finally cooled to room temperature. The presence of pearlite at room temperature decreases the ductility of samples annealed at T > Ac1.

Superplasticity and Microstructure Evolution of Electrodeposited Nanocrystalline Nickel

2007 ◽  
Vol 551-552 ◽  
pp. 539-544 ◽  
Author(s):  
S. Ding ◽  
Kai Feng Zhang ◽  
Guo Feng Wang
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Room Temperature ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Intergranular Cracking ◽  
Mean Grain Size ◽  
Electrodeposited Nickel ◽  
Superplastic Properties

Nanocrystalline pure nickel (nc-Ni) was produced by pulse electrodeposition and its superplastic properties at and above room temperature were investigated. The electrodeposited nickel has a narrow grain size distribution with a mean grain size of 70nm. Uniaxial tensile tests at room temperature showed that nc-Ni has a limited plasticity but high tensile strength up to 1GPa at strain rates between 10-5 and 10-2s-1. However, when the temperature increased to 420 and higher, test specimens showed uniform deformation and the elongation value was larger than 200%. A maximum elongation value of 380% was observed at 450°C and a strain rate of 1.67x10-3s-1, SEM and TEM were used to examine the microstructures of the as-deposited and deformed specimens. The results indicated that fracture was caused by intergranular cracking and most cracks were originated from the brittle oxide formed during the tensile test. Grain coarsening was observed in the deformed specimen. The role of temperature and strain on grain growth was evaluated by comparing the microstructure of deformed samples with that of samples statically annealed. Deformation mechanism was discussed based upon the deformed microstructure and strain rate jump tests.

Experimental Study on the Mechanical Property and Forming Limit of Magnesium Sheet at Elevated Temperatures

2009 ◽  
Author(s):  
Y. Huang ◽  
J. Huang ◽  
J. Cao
Keyword(s):  
Elevated Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Tensile Tests ◽  
Alloy Sheet ◽  
Dome Height ◽  
Forming Limit ◽  
Uniaxial Tensile ◽  
Magnesium Sheet

Magnesium alloy sheet has received increasing attention in automotive and aerospace industries. It is widely recognized that magnesium sheet has a poor formability at room temperature. While at elevated temperature, its formability can be dramatically improved. Most of work in the field has been working with the magnesium sheet after annealed around 350°C. In this paper, the as-received commercial magnesium sheet (AZ31B-H24) with thickness of 2mm has been experimentally studied without any special heat treatment. Uniaxial tensile tests at room temperature and elevated temperature were first conducted to have a better understanding of the material properties of magnesium sheet (AZ31B-H24). Then, limit dome height (LDH) tests were conducted to capture forming limits of magnesium sheet (AZ31B-H24) at elevated temperatures. An optical method has been introduced to obtain the stress-strain curve at elevated temperatures. Experimental results of the LDH tests were presented.

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