The nanoscale strength of ultra nano crystalline diamond

These metrics are regularly updated to reflect usage leading up to the last few days. Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.

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The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric. Find more information on the Altmetric Attention Score and how the score is calculated. Charging current is monitored by conductive AFM. Electric potential contrast induced by the current is evaluated by Kelvin force microscopy KFM. KFM shows well-defined, homogeneous, and reproducible microscopic patterns that are not influenced by inherent tip—surface junction fluctuations during the charging process.

The charged patterns are persistent for at least 72 h due to charge trapping inside the NCD film. In addition, we show that the field also determines the range of electronic states that can trap the charge. We present a model and discuss implications for control of the nanoscale charging process.

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Control of Nanoscale Environment to Improve Stability of Immobilized Proteins on Diamond Surfaces

Cite this: Langmuir2923— Article Views Altmetric. Citations 4. Cited By. This article is cited by 4 publications. Micromachines9 6 Surface potential of nanodiamonds investigated by KPFM.

Berhane, Igor Aharonovich, Hugues A. Photoluminescence of nanodiamonds influenced by charge transfer from silicon and metal substrates. Diamond and Related Materials63 Journal of Materials Chemistry C3 48These metrics are regularly updated to reflect usage leading up to the last few days. Citations are the number of other articles citing this article, calculated by Crossref and updated daily.

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the nanoscale strength of ultra nano crystalline diamond

Clicking on the donut icon will load a page at altmetric. Find more information on the Altmetric Attention Score and how the score is calculated. Nanoscale, single-asperity wear of single-crystal silicon carbide sc-SiC and nanocrystalline silicon carbide nc-SiC is investigated using single-crystal diamond nanoindenter tips and nanocrystalline diamond atomic force microscopy AFM tips under dry conditions, and the wear behavior is compared to that of single-crystal silicon with both thin and thick native oxide layers.

We discovered a transition in the relative wear resistance of the SiC samples compared to that of Si as a function of contact size.

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This conclusion is supported by our AFM studies of wearless friction, which reveal that the interfacial shear strength of SiC is higher than that of Si. The contributions of surface roughness and surface chemistry to differences in interfacial shear strength are also discussed. The American Chemical Society holds a copyright ownership interest in any copyrightable Supporting Information. Files available from the ACS website may be downloaded for personal use only.

Users are not otherwise permitted to reproduce, republish, redistribute, or sell any Supporting Information from the ACS website, either in whole or in part, in either machine-readable form or any other form without permission from the American Chemical Society. For permission to reproduce, republish and redistribute this material, requesters must process their own requests via the RightsLink permission system.

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Citations Supporting Information. Cited By. This article is cited by 12 publications. Streed, and Dzung Viet Dao. Materials13 7 Racz, D. Dworschak, M. Valtiner, M. Scratching resistance of SiC-rich nano-coatings produced by noble gas ion mixing. Surface and Coatings Technology, Tribochemical wear of silicon nitride against silicate and phosphate glasses.

Wear, Microgravity Science and Technology31 1 Mechanical and tribological performances of C-SiC nanocomposites synthetized from polymer-derived ceramics sintered by spark plasma sintering. Ceramics International44 12 Edge orientation dependent nanoscale friction.

Nanoscale10 5 Molecular dynamics simulation in single crystal 3C-SiC under nanoindentation: Formation of prismatic loops. Ceramics International43 18Pristine monocrystalline graphene is claimed to be the strongest material known with remarkable mechanical and electrical properties.

However, graphene made with scalable fabrication techniques is polycrystalline and contains inherent nanoscale line and point defects—grain boundaries and grain-boundary triple junctions—that lead to significant statistical fluctuations in toughness and strength.

These fluctuations become particularly pronounced for nanocrystalline graphene where the density of defects is high.

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We develop the first statistical theory of toughness in polycrystalline graphene, and elucidate the nanoscale origins of the grain-size dependence of its strength and toughness. Our results should lead to more reliable graphene device design, and provide a framework to interpret experimental results in a broad class of two-dimensional materials.

The high strength of graphene combined with its exceptional electronic 12optical 3 and thermal properties 4 has made it an ideal material for many fascinating applications, including flexible electronic displays 5corrosion-resistant coatings 6biological devices 78 and many more 9. While each of these applications exploits a different key property of graphene, they all implicitly depend on its exceptional mechanical properties for structural reliability However, such mechanical reliability of graphene is impacted by atomic defects in its structure.

While the effect of relatively simple defects, such as isolated dislocation cores or a few special grain boundaries GBon the strength of graphene is understood 11121314151617the statistical fluctuations in strength and toughness due to the randomness in polycrystalline nanostructure remains largely unexplored. Strength and toughness are arguably the two most important properties of a structural material.

While strength is generally a function of the material's resistance to deformation, toughness represents its resistance to fracture.

In most materials, these properties tend to be mutually exclusive There are conflicting experimental reports whether the strength of polycrystalline graphene is actually a function of grain size 192021 making the role of simulation and theory more critical.

It is well-established that the strength and toughness of polycrystalline solids is strongly influenced by their granular structure. For instance, nanocrystalline metals are invariably significantly harder and much less ductile than their microcrystalline counterparts. On the other hand, dislocations are typically not mobile in brittle materials, such as ceramics and grapheneand thus the Hall—Petch effect is not observed in these materials.

In contrast to typical bulk brittle materials such as ceramics, graphene can be fabricated in a much cleaner and controlled environment, thus making the presence of large extrinsic defects unlikely In the absence of such extrinsic defects, the fluctuations in strength must arise from intrinsic atomic defects inherent to the granular nanostructure. The traditional theories developed for brittle ceramics with large extrinsic flaws are thus not applicable for strength fluctuations due to these intrinsic defects.

In graphene these defects are GBs and triple junctions TJs. Although a GB is an interface between crystalline regions of different lattice orientations and a TJ is the intersection of three such interfaces, in graphene GBs and TJs are typically composed of pentagon—heptagon defects, also known as five to seven defects Fig.

These defects involve significant residual stresses and act like stress concentrators. The defected atoms at the GBs and TJs that are part of non-hexagon rings are drawn in red for clear identification.

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The red arrows indicate the orientation of the grains on either side of the GB; the GB itself is composed of rings of five coloured pink and seven coloured blue carbon atoms. These are the dislocation cores with the shortest Burgers vectors in graphene, and thus represent low-energy configurations of GBs.In all theseapplications, the quality and integrity of the tip used to obtain theimages or interrogate materials is paramount.

A common problem in atomic force microscopy is the deterioration ofthe tip apex as surfaces are scanned. To overcome this problem, a teamof scientists from Northwestern University and Argonne NationalLaboratory report the microfabrication of monolithicultra-nano-crystalline diamond UNCD cantilevers with tips exhibitingproperties similar to single-crystal diamond.

Their results arepublished in the Aug. Diamond, the hardest known material, is probably the optimal tipmaterial for many applications. In addition to hardness, diamond isstiff, biocompatible and wear resistant. Until now, commerciallyavailable diamond AFM tips are either glued to a microcantilever avery slow and non-scalable manufacturing approach or made by coating asilicon tip manufactured using conventional microfabricationtechniques.

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Chemical vapor deposition CVD techniques for growing thinfilms of synthetic diamond typically do not produce single-crystalfilms, in which atoms are all oriented in a regular lattice. UNCD, amaterial discovered at Argonne in the s, is the closest diamondatomic structure in which the material is organized in very smallgrains a few nanometers in size leading to smooth surfaces easy tomold and shape by microfabrication techniques. The similarity of UNCDto single-crystal diamond and its superiority to silicon, siliconcarbide and other micro- and nanoelectromechanical systems MEMS andNEMS materials, in the context of strength, toughness and wearperformance, has been established.

The standard MEMS microfabrication techniques used for the diamond tips-- an important feature of this development -- provides scalability tomassively parallel arrays of probes for high throughput. Moreover, the possibility ofdoping the material to make it conductive is very exciting and opens alarge number of opportunities for scientific discovery.

The technology can be employed fora variety of AFM scanning modes, from regular surface scanning in airor fluids to conductive AFM. It can also be employed as ananofabrication tool. Examples include nanolithography inorganic inkdispensingdetecting and repairing failure of micro- and nano-electronic devices, nanopatterning of biomolecules for sequencing,synthesis and drug discovery and scanning probe electrochemistry scanning electrode imaging, localized electrochemical etching ordeposition of materials and nanovoltametry.

Potential markets include those industries where it is pivotal topreserve the performance of the tips or that require two-dimensionalarrays for high throughput in which the cost of manufacturing is suchthat minimum possible tip wear is paramount. Examples include themicroelectronics industry novel random-access memories based on AFMtechnology, such as IBM's Millipedethe semiconductor industry photomask repair and the chemical and biological sensor industrywhere high throughput and spatial resolution are important.

Northwestern is seeking a licensing partner to commercialize themicrofabrication processes and methods to produce arrays of the device. A patent application has been filed by the University. Materials provided by Northwestern University. Note: Content may be edited for style and length.Federal government websites often end in.

The site is secure. Test specimens include as deposited thin films, in addition to theta and C-ring structures fabricated using lithography and deep reactive ion etching, focused ion-beam machining, and laser machining. We are designing, fabricating, and testing specialty test structures largely based on a theta geometry. The theta test specimen is a simple and elegant way to measure the mechanical properties of materials at ultra-small length scales without the need for special grips.

Nanoscale Strength Measurements for Device Technologies

The test specimen is diametrally compressed via instrumented indentation, or nanoindentation, which places the central "web" section in uniform tension.

Finite element method FEM modeling is used to design robust specimen and loading configurations. Emphasis is placed on measuring strength, fracture resistance, and compliance. Fractography is used to correlate mechanical testing results to fabrication conditions. Methods to fabricate, inhouse, silicon Si test structures with deep reactive ion etching DRIE have been developed. In addition to the theta test structure, we are also investigating a new C-ring structure to measure nano-scale bending strengths.

MEMS and NEMS components are typically formed via lithographic and etching processes, which are known to leave residual surface features, stresses, and chemical remnants that ultimately control component strength.

It is still not clear, however, how these surface characteristics interact with loads and deformations imposed during device operation to induce failure and truncated lifetimes. Thus, the development of new mechanical test structures and methodologies to measure the mechanical properties of materials at ultra-small length scales is required.

To address this measurement need, a first-generation of test specimens was fabricated from Si by through-wafer DRIE and tested using load-controlled instrumented indentation. The test specimens consisted of round and hexagonal theta geometrics. From linear-elastic fracture mechanics, these average fracture stresses correspond to critical flaw sizes of nm to nm. In fact, fractography of the broken web sections indicated that fractures typically originated at etch pits from the DRIE.

The etch pits ranged in depth from nm to nm. Thus, it is clear from these preliminary studies that the etch pits acted as strength limiting flaws that ultimately controlled the overall strength of the component. The first generation test structures, in addition to demonstrating the viability of the measurement technique, also illustrated problems with the test method that needed to be addressed prior to broader implementation: mounting the specimens for testing was difficult, non-ideal loading led to undesirable stress concentrations,and collecting the specimen parts for fractography after failure was difficult.

Thus, a second generation of structures was developed. Test specimens included two theta geometries, the original design and a triple fillet design, and a new C-ring geometry to measure nano-scale bending strengths. The new specimens were designed with "top hats" to minimize misalignments and stress oncentrations,fabricated using silicon-on-insulator SOI wafers to provide better control of device thickness and more robust bases for. The force-displacement curves were linear to fracture.

Fracture strengths as high as 2. As with the first generation samples, fractography revealed that etch pits from the DRIE process acted as strength limiting flaws.

Alternative DRIE processes to generate different surface finishes are being investigated, thus allowing the sensitivity of strength and fracture properties to surface structure to be assessed.

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In addition, although emphasis is currently on Si test structures, other materials such as poly-Si, SiC, poly-diamond, and alumina will be investigated through collaborative activities.

Project Summary PDF. Share Facebook. ElectronicsMetrologyNanomechanics and Nanometrology. Created November 25,Updated September 3, Today, high school students can dabble in nanoscience thanks to the U.

The wires become the essential components to fabricate optical and electrical sensors, similar to the technology used in pressure sensors and other simple devices, in a matter of a few minutes.

The opportunity came when chemist Mike Zach, former Center for Nanoscale Materials facility user and current researcher at Oak Ridge National Laboratoryapproached Sumant to develop a simple electrochemical method to mass produce micro- and nanowires. Students can use it again and again since diamond is chemically inert and does not strongly adhere to metals.

Together, the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative.

About United Scientific Supplies, Inc. United Scientific Supplies, Inc. Its products are manufactured in modern factories worldwide and distributed from the United warehouse in Waukegan, Illinois. United has been serving the needs of the scientific community sinceand is celebrating its 25 th anniversary this year.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology.

the nanoscale strength of ultra nano crystalline diamond

The U. For more information, visit the Office of Science website. August 18, For years, scientists have been creating and tweaking extremely tiny materials atom by atom in special clean rooms scrubbed of debris. Students needed a Ph. Image by Argonne National Laboratory.Nanodiamonds or diamond nanoparticles are diamonds with a size below 1 micrometre.

Because of their inexpensive, large-scale synthesis, potential for surface functionalization, and high biocompatibility, nanodiamonds are widely investigated as a potential material in biological and electronic applications and quantum engineering.

InSoviet scientists at the All-Union Research Institute of Technical Physics noticed that nanodiamonds were created by nuclear explosions that used carbon-based trigger explosives. There are three main aspects in the structure of diamond nanoparticles to be considered: the overall shape, the core, and the surface.

the nanoscale strength of ultra nano crystalline diamond

Through multiple diffraction experiments, it has been determined that the overall shape of diamond nanoparticles is either spherical or elliptical. At the core of diamond nanoparticles lies a diamond cage, which is composed mainly of carbons. A recent study shows that the surface consists mainly of carbons, with high amounts of phenols, pyrones, and sulfonic acid, as well as carboxylic acid groups, hydroxyl groups, and epoxide groups, though in lesser amounts.

the nanoscale strength of ultra nano crystalline diamond

Other than explosions, methods of synthesis include hydrothermal synthesis, ion bombardment, laser bombardment, microwave plasma chemical vapor deposition techniques, ultrasound synthesis, [10] and electrochemical synthesis. Detonation synthesis utilizes gas-based and liquid-based coolants such as argon and water, water-based foams, and ice. In general, gaseous ozone treatment or solution-phase nitric acid oxidation is utilized to remove sp2 carbons and metal impurities. Applying a microwave pulse to such a defect switches the direction of its electron spin.

Applying a series of such pulses Walsh decoupling sequences causes them to act as filters. Varying the number of pulses in a series switched the spin direction a different number of times. Nanodiamonds share the hardness and chemical stability of visible-scale diamonds, making them candidates for applications such as polishes and engine oil additives for improved lubrication.

Diamond nanoparticles have the potential to be used in myriad biological applications and due to their unique properties such as inertness and hardness, nanodiamonds may prove to be a better alternative to the traditional nanomaterials currently utilized to carry drugs, coat implantable materials, and synthesize biosensors and biomedical robots.

In vitro studies exploring the dispersion of diamond nanoparticles in cells have revealed that most diamond nanoparticles exhibit fluorescence and are uniformly distributed.

They have unique optical, mechanical and thermal properties and are non-toxic. The potential of nanodiamond in drug delivery has been demonstrated, fundamental mechanisms, thermodynamics and kinetics of drug adsorption on nanodiamond are poorly understood. Important factors include purity, surface chemistrydispersion quality, temperature and ionic composition.

Nanodiamonds with attached molecules are able to penetrate the blood-brain barrier that isolates the brain from most insults. In doxorubicin molecules a popular cancer-killing drug were bonded to nanodiamond surfaces, creating the drug ND-DOX. Tests showed that tumors were unable to eject the compound, increasing the drug's ability to impact the tumor and reducing side-effects. Larger nanodiamonds, due to their "high uptake efficiency", have the potential to serve as cellular labels.

Decreasing particle size and functionalizing their surfaces [18] may allow such surface-modified diamond nanoparticles to deliver proteins, which can then provide an alternative to traditional catalysts. Nanodiamonds are well-absorbed by human skin.


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