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'World's first' fully-electric commercial flight takes off

Posted By Graphene Council, Thursday, December 12, 2019

An all-electric powered seaplane has taken flight in Vancouver, Canada, in what the operators describe as a "world first" for the aviation industry.

The short test flight by Harbour Air and magniX involved a six-passenger aircraft fitted with an electric motor.

The companies said it was a first step to building the "world's first all-electric commercial fleet".

The push to electric could help slash carbon emissions in the high-polluting aviation sector.

"This historic flight signifies the start of the third era in aviation - the electric age," Harbour Air and magniX said in a statement.

The flight involved a six-passenger DHC-2 de Havilland Beaver with a 750-horsepower (560 kW) magni500 propulsion system.

Launched at the Paris Air Show earlier this year, Australian company magniX said its propulsion system aims to provide a "clean and efficient way to power airplanes".


Could aviation ever be less polluting?

Canadian seaplane operator Harbour Air hopes to electrify its entire fleet by 2022, provided it secures safety and regulatory approvals.

Electric ambitions

Shifting to electric engines is seen as one way to cut greenhouse gas emissions in the aviation sector.

It comes amid growing concern from travellers over the polluting impacts of flying.

In the UK, aviation is set to be the biggest source of emissions by 2050.

A recent survey by Swiss bank UBS found people are beginning to cut air travel over concern for the environment - as the Swedish concept of "flygskam" or "flight shame" appeared to spread.

Still, electric aircraft that can travel long distances remain a big challenge for the sector.

Electrical motors, generators, power distribution and controls have advanced rapidly but battery technology has not.

An aircraft like the one flown in Vancouver could only fly about 160km (100 miles) on lithium battery power, according to AFP.

"The [flight] range now is not where we'd love it to be, but it's enough to start the revolution," said magniX chief executive Roei Ganzarski, the news agency reported.

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Commentary - Between EV's, distributed electrical generation (and storage), renewable power generation and the need for grid balancing, and now potential use in at least commuter aircraft, the need for higher energy density batteries has never been greater and will only grow. Even if graphene plays only a small role as part of that solution it will be an important market. TB

Tags:  Graphene  Harbour Air  magniX 

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Entrepreneur has sustainability challenge covered - with a SpaceMat

Posted By Graphene Council, Thursday, December 12, 2019
An entrepreneurial academic from The University of Manchester has produced a prototype graphene-enhanced product that could help the UK recycle tonnes of unwanted tyres – a waste product that is sometimes shipped overseas for disposal.

It is claimed that Western countries like the UK export waste tyres to developing nations like India where they are destroyed by burning - and so impacting on the local environment.

Dr Vivek Koncherry has launched a company called SpaceBlue Ltd that aims to recycle waste tyres by converting them into attractive and extremely hardwearing floor mats which have been enhanced with tiny amounts of graphene.

The hexagon-shaped SpaceMat™ can interlock to cover any desired floor area. They can be used at the entrances of homes, offices, public and industrial buildings, as well as wider applications such as anti-fatigue or anti-slip coverings in areas like workplaces, gyms, playgrounds and swimming pools.

Prototype mats will be revealed at a Graphene Industry Showcase to be hosted on December 10 and 11 at the Graphene Engineering Innovation Centre (GEIC). This two-day event aims to put a spotlight on innovations associated with graphene and two-dimensional materials and will therefore feature a wide range of pioneering products.

“The innovation ecosystem at Manchester has been really supportive to someone like me who has a new business idea they want to take to market,” explained Dr Koncherry, who is an expert in materials applications and new manufacturing techniques.

“It all began when I first read newspaper reports that several thousand tonnes of waste UK tyres are being shipped abroad each year for disposal. I thought that needs to change and I became determined to find a much more sustainable way of using this end-of-life product.

“The intention of SpaceBlue is to enhance the physical properties of recycled rubber waste that has come from discarded vehicle tyres or footwear - and convert this material into a high-value product,” explained Dr Koncherry.

“The intention of SpaceBlue is to enhance the physical properties of recycled rubber waste that has come from discarded vehicle tyres or footwear - and convert this material into a high-value product”
Dr Vivek Koncherry

“SpaceMat™ is made of up to 80 per cent recycled rubber plus 20 per cent of graphene-enhanced natural rubber. Floor mats undergo compression and a fundamental study had shown that by adding graphene into the rubber it can double the compression strength - and this in turn increases durability.”

James Baker, CEO of Graphene@Manchester, added: “Vivek’s vision to support a more sustainable society by creating a better performing product through the use of graphene is really exciting and has already generated interest.

“Moreover, we’re looking forward to collaborating with SpaceBlue via our ‘Bridging the Gap’ programme which will further support the development of the mats.”

Funded by the European Regional Development Fund (ERDF) the ‘Bridging the Gap’ initiative has been developed to proactively engage with small and medium enterprises (SMEs) in Greater Manchester and allow them to explore and apply graphene and other advanced two-dimensional materials in a wide range of applications and markets.

Tags:  Graphene  Graphene Engineering Innovation Centre  James Baker  University of Manchester  Vivek Koncherry 

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On the quantum dance floor, the 'twist' is king

Posted By Graphene Council, Thursday, December 12, 2019
In 1986, two relatively unknown physicists, working in a laboratory on a Swiss hilltop, made a discovery that started a revolution.

“It was the Woodstock of condensed matter physics,” said Enrico Rossi, associate professor of physics at William & Mary. “People were so excited. It changed everything.”

Physicists J. Georg Bednorz and K. Alex Mueller discovered superconductivity in ceramic material, specifically lanthanum-based cuprate perovskite, and created the first high-temperature superconductor.

The discovery earned them the 1987 Nobel Prize in Physics and held the promise that one day it could be feasible to transmit electricity and information over vast distances with virtually no loss of current or data.

“They were basically playing with this ceramic material and found that it became a superconductor at temperatures well above absolute zero, well above the limit that theory predicted was possible,” Rossi said.

The typical flow of electric current, the kind that powers the average household, is a charge carried by electrons that move through a circuit made from copper wiring. The electrons move from one atom to another as they travel through the wiring, which creates a current that provides power to the home. 

With copper, and almost any other material, there is a certain level of resistance against the moving electrons, sort of like air resistance pushes back on a thrown tennis ball. The less resistance, the better the electrons can move and the current will flow more freely. Superconductivity is a phenomenon in which the resistance against an electric current flowing through a material is zero.

The problem with superconductivity is that it happens at very low temperatures, close to 0 Kelvin or -459.67 degrees Fahrenheit. The idea of room-temperature superconductivity is something like the El Dorado of materials science, Rossi explained.

Such a discovery would pave the way for ultrafast computers, far more efficient power transmission and high-speed trains that could travel hundreds of miles per hour with little power. For now, the City of Gold remains elusive. Bednorz and Mueller earned their Nobel for reaching superconductivity at 35 Kelvin, or -396.67 degrees Fahrenheit.

“There was the hope that we could go all the way up to room temperature,” Rossi said. “That would be a true revolution, because you could have no dissipation in everyday connections. But we’re stuck in lower temperatures and, from an academic perspective, we still don’t understand why these ceramic materials are superconducting.”

Rossi says part of the difficulty may be that ceramic materials have a complicated chemical structure that makes it challenging to identify the key ingredients that lead electrons to superconduct. He and Xiang Hu, a postdoc research assistant in the university’s Department of Physics, are co-authors on a paper recently published in Physical Review Letters, the American Physical Society’s flagship publication.

The duo collaborated with researchers from Microsoft Quantum and the Polish Academy of Sciences to examine what leads electrons to superconduct in twisted bilayer graphene. Their work was supported by an NSF-CAREER grant, the Office of Naval Research, the Army Research Office and the United States-Israel Binational Science Foundation. 

Twisted bilayer graphene is a material made from taking a one-atom-thick layer of carbon atoms and folding it over on itself at a slight angle, 1.05 degrees. By folding it at that precise angle (what physicists call the “magic angle”), the atoms line up in such a way that the material becomes a superconductor.

The fundamental mechanism that leads to superconductivity might be the same as in the ceramic materials, but the chemical structure of twisted bilayer graphene is much simpler, Rossi explained. The revelation started a new field called "twistronics" and opened the door for researchers like Rossi and Hu to study the underlying physics of superconductivity.

“It’s really about the way the system is engineered,” Rossi said. “Take, for example, something like chalk. You can break a brick of chalk really easily, but that same material makes shells, which can last for centuries. It has to do with the nature of how the atoms are arranged. That same principle applies for creating superconductivity in graphene.”

Rossi and the team of researchers found that the specific arrangement of atoms, and the way such arrangement affects the quantum state of each electron, can explain why electrons in graphene superconduct.

It helps to think of the phenomenon as a kind of quantum square-dance, with the folded matrix on which the atoms are arranged as the dance floor. The dancers are electrons, who, as the evening goes on, couple up with other electrons in groupings called Cooper pairs, a key element of superconductivity.              

“In twisted bilayer graphene, the electrons are forced to move slowly. If you slow them down, make the velocity very small, and you allow the electrons to spend more time in the same place, they start interacting and pairing up,” Rossi said. “Naively, you would also expect that to lead to pure superconductivity, because the electrons have enough time to form pairs and form a lot of them. However, if these Cooper pairs are all by themselves, doing their own thing, then the system is not going to superconduct and conventional results suggest that this would be the case in twisted bilayer graphene.”

In simpler terms, to achieve superconductivity, the quantum square-dance must become a giant conga line with all the Cooper pairs joining together. If couples keep to themselves, the material doesn’t superconduct. Rossi, Hu and their collaborators discovered how this happens in twisted bilayer graphene, despite the extremely small velocity of the electrons.

“The way I like to explain it is that somehow they all need to link arms,” Rossi said. “Imagine there is a chain of people and they’re all going forward, but then they hit an obstacle. If the pairs aren’t linked together, then one pair will stop when they hit the obstacle and the other may keep going.”

If only half the pairs are getting around the obstacle, Rossi explained, then the amount of current the system can carry is cut in half, causing electrical resistance. Half of the pairs are getting stuck. If all the electrons are able to link together, then they can pull each other past obstacles and the electrical resistance shrinks to zero.

“The strength of this linkage is really important,” Hu said. “Using previous results, one would conclude that such strength would be vanishingly small in twisted bilayer graphene. The fact that it's possible for the linkage to be present in twisted bilayer graphene has not been examined before now.” 

Once the researchers realized that the “conga line” formation in twisted bilayer graphene was crucial for superconductivity, they set out to figure out why it happens. Instead of looking at the dancers, the team looked at how they dance.

They found it was actually the individual nature of each couple (the electron pairs’ individual attributes, analogous to spin) that had the greatest impact on linkage. It had a greater impact than their size or speed or how much time they spent on the quantum dance floor.

“At first, the focus was on the velocity. When it goes to zero, you can form couples and that’s great, but it’s not enough,” Rossi said. “You need to be able to make all those couples somehow link up. That’s what you need to get superconductivity. The assumption was that this linking was also due to the velocity, but that was neglecting the fact that there is another way. It has to do with the individual features of the quantum states. It’s a contribution people hadn’t considered before.”

Tags:  Enrico Rossi  Graphene  J. Georg Bednorz  K. Alex Mueller  William & Mary  Xiang Hu 

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Jose A. Garrido’s vision: graphene bioelectronic eye implants

Posted By Graphene Council, Thursday, December 12, 2019
Jose A. Garrido is an ICREA Research Professor and leader of the Advanced Electronic Materials and Devices group at Graphene Flagship partner ICN2, in Barcelona. He is also the Deputy Leader of the Graphene Flagship's Biomedical Technologies Work Package, and he has a vision: a world in which doctors can cure diseases and disabilities using biomedical implants enabled by novel electronic materials like graphene.

His pioneering work on graphene-enabled retinal implants, which aim to provide artificial vision to patients with retinal degeneration, is internationally recognised – Garrido and his collaborators have recently been awarded a €1 million grant by the la Caixa Foundation to fund their research. He plans to use the money to enable an ambitious three-year project to design the next generation of retinal prostheses using graphene-based electrodes.

I spoke with Garrido at the Graphene Connect event in Barcelona, this November, and gained some fantastic insights into the work he's doing and his ideas for the future of medical bioelectronic devices.

What motivated you to start working on retinal implants?


In general, I'm very interested in merging electronics with biology to solve health problems. It started before trying to solve vision problems – in general, I've always been interested in how we could use electronics to help patients. But years ago, some people I was working with in France made me start thinking about the problem of blindness, and how it affects people. I thought that this would be a good bench test for our technologies, and a great platform for me to try to understand the challenges of restoring vision. I wanted to investigate how graphene electronics could solve these challenges.

Why use graphene?

Well, firstly, I started with other materials. Years ago, I was working with materials that are also chemically resistant, such as semiconductors like gallium nitride, and then I moved to diamond because it was stable as well. However, for each of these materials, we always had some sort of trouble! Either the flexibility was a problem, the material was not sensitive enough, or we couldn't inject sufficient charge. But when graphene came, everything changed. The fact is, we haven't found a reason not to work with graphene yet. It has a combination of properties that make it very attractive.

What makes graphene so good for biomedical devices?

Firstly, for this application, I believe the ability to integrate graphene with flexible technologies is the most important. You need to integrate it into a flexible substrate and do all the fabrication and microfabrication required to produce your device.

It also needs to be able to interface with the nervous system, to stimulate and to monitor electrical activity. In order to have a proper interface with the nervous system, you can't just have either recording or simulation. You need both to enable bidirectional communication. So far, graphene is very good at stimulating and recording nervous tissue. We can easily integrate it into flexible substrates, and it's a durable material when exposed to a harsh environment.

Could you explain to me how the retinal implants function in layman's terms?

We're trying to help patients who have degenerated photoreceptors. This happens in several neurodegenerative diseases such as retinitis pigmentosa or age-related macular degeneration. But this degeneration does not mean that the whole retina is degenerated. There are some parts of the retina that are still intact, and those are still connected to the optical nerve.

One solution is to have photoreceptors which stimulate the intact part of the retina, and then transfer that information through the optical nerve to the visual cortex.

We're taking a different approach. We don't use the photoreceptors – instead, we plan to implant an array of graphene-based electrodes on the retina. These electrodes mimic photoreceptor stimulation with an electrical impulse. It works like this: an image is captured with an external camera, then this information is sent wirelessly to the implant, received in the form of pulses applied to each of the electrodes on the implant. This effectively copies the function of the photoreceptors and should allow the patient to see a pixelated image.

What would you say are the challenges going forward?

When it comes to integrating graphene, we're at a pre-industrial level. But over the last four years, thanks to the Graphene Flagship, among other projects, we've gone from being research-orientated to actually applying that research. We have pre-industrial device prototypes, and we do fabrication in cleanrooms – the same cleanrooms we use for research. For me, I think that that integration and demonstration of the prototypes is not the challenge. The challenge is industrialisation.

How can we jump from what we do in a pre-industrial cleanroom to large-scale fabrication? Who is going to mass-produce these technologies? Right now, there's no one in Europe who can do this type of production on such a large scale, with the required levels of standardisation.

That's the main challenge for a lot of applications of graphene, and we're all suffering from the same problems. The Graphene Flagship have now realised this, and that's why they have launched the Standardisation and Validation services, and will soon launch the Experimental Pilot Line. This is a very important effort, but it will have to be matched by industry.

What ultimately led to you being awarded the grant?

Competition was very tough, I can tell you! They really valued the multidisciplinary team that we put together – it's really unique to have such a strong team with such different backgrounds, sharing the costs and responsibilities. Each of us was an expert in our field, and we just really wanted to work together. Experts in optical imaging were from ICFO, experts in electronics and ASIC design came from IFAE, clinicians were from the Barraquer Foundation, and the Paris Vision Institute provided experts in retina electrophysiology.

How are you going to use the €1 million grant?

We need to develop some understanding of the challenges. The challenges are not only at the interface with the tissue – there are challenges with the wireless transmission, with the design of the specialized chip controlling the whole system, and with the powering of the device. How do you power a device that small?

This grant is going to be crucial to bring together such a multidisciplinary team. A team that knows about optics, wireless transmission, neural interfaces, materials science and biology. Of course, we're going to divide the pie into many pieces. But we hope that when we put these pieces together, the project will be a great success.

Finally, where do you see graphene-enabled retinal implants in 10 years?

In 10 years, the project should be a commercial success! I think that in just three years, we should have demonstrated some of the hypotheses that we are proposing now. Without doubt, there's a huge amount of work to be done if we want to help patients to recover part of their lost vision, not to mention the promise of a complete recovery – but our technology will also lead to significant improvements in many other fields where medical neural implants are currently used, including brain surgery, epilepsy monitoring, and movement disorders such as Parkinson's disease.

Tags:  Bioelectronics  electronic materials  Graphene  Graphene Flagship  Healthcare  Jose A. Garrido 

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World's First Verified Graphene Product™ Announced

Posted By Graphene Council, Wednesday, December 11, 2019

The world's first Verified Graphene Product™ has been approved by The Graphene Council.

MediaDevil’s CB-01 earphones make use of Nanene® graphene from Versarien in the CB-01’s audio diaphragm, enabling simultaneous optimisation of both the high and low-end audio frequencies. 

From FORBES:  "The detail the CB-01 earphones managed to squeeze from the music was captivating. These are remarkable."
 "...The CB-01 earphones from MediaDevil are a revelation. They are the first pair of graphene-coated earphones that made me sit up and take notice." 

Media Devil uses the finest materials and highly-skilled artisans to create premium quality products. These include full-grain European leather, Italian Rosewood, or precision engineered Aramid Fibre. And now Graphene, providing Media Devil customers with a unique experience.


Versarien (the supplier of Nanene™ graphene materials to Media Devil) is the first company in the world to pass the rigorous Verified Graphene Producer™ program administered by The Graphene Council.

This program involves an in-person inspection of graphene production facilities, analysis of random samples of graphene products and independent testing and characterization of the material by internationally recognized and qualified labs, such as the National Physical Laboratory (NPL) in the UK. 

Versarien uses proprietary materials technology to create innovative engineering solutions that are capable of having game-changing impact in a broad variety of industry sectors.

The Verified Graphene Producer™ and the Verified Graphene Product™ programs provide the world's most thorough, independent validation service, adding a level of transparency not available anywhere else and is based on the most up-to-date standards and testing protocols. 

This will be increasingly important to end-users and buyers of graphene as they search for reliable sources of supply.

 

Tags:  Graphene  Graphene Council  National Physical Laboratory  Versarien 

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XG Sciences and Perpetuus Partner to Supply Graphene to the North American Tire Markets

Posted By Graphene Council, Wednesday, December 11, 2019
XG Sciences, Inc., a market leader in the design and manufacture of graphene nanoplatelets and advanced materials containing graphene nanoplatelets, announced it has  entered into Commercialization and License Agreements with Perpetuus Advance Materials, a market leader in the production of dispersible, surface-modified graphene to optimize their performance in a range of matrices and end-use markets.

The Agreements provide the commercial framework allowing the two companies to more closely collaborate in the exclusive supply of functionalized graphene into the North American market and to also collaboratively develop applications for the global marketplace.  Initially, the Companies will focus efforts on elastomers, with an emphasis on tires and related applications, but may expand the relationship over time to include other markets and applications.  Under the Agreements, Perpetuus will locate one or more of its patented, plasma-based surfaces-modification production plants in the U.S. near one of XG Sciences’ graphene nanoplatelet production facilities.  The collaboration contemplates both product development collaboration and high-volume commercial supply.

First isolated and characterized in 2004, graphene is a single layer of carbon atoms. Among many noted properties, monolayer graphene is harder than diamonds, lighter than steel but significantly stronger, and conducts electricity better than copper. Graphene nanoplatelets are particles consisting of multiple layers of graphene with unique capabilities for energy storage, thermal conductivity, electrical conductivity, barrier properties, lubricity and the ability to impart physical property improvements when incorporated into plastics, metals or other matrices.

“We have been working with Perpetuus in various commercial and development efforts for the past several years.  This Agreement represents a key milestone in the commercial adoption of graphene and establishes XG Sciences and Perpetuus as marque players in the supply of graphene for use in tire elastomers and other applications,” said Dr. Philip Rose, CEO, XG Sciences. “The North American elastomer market, especially those used in tires is substantial.   Perpetuus has unique technology with demonstrated performance enhancements when incorporated into tires.  Tires will likely represent one of the break-out applications for graphene and we are now well-positioned with Perpetuus to deliver solutions to the elastomer market,” said Bamidele Ali, Chief Commercial Officer, XG Sciences.

“XG Sciences is a well-known leader in the graphene field and is an ideal choice with whom to partner to bring our technology to this important market,” said John Buckland, CEO, Perpetuus.

“We are familiar with XG Sciences’ graphene nanoplatelets and we have been utilizing them as input materials to our patented, surface-modification process and supplying the resulting high-performance graphenes to both commercial and developmental customers in a range of applications and markets.  It is a natural fit to partner our two Companies and leverage our respective capabilities to serve the North American market for elastomers,” said Ian Walters, Director and COO, Perpetuus.

Tags:  Bamidele Ali  energy storage  Graphene  Perpetuus Advanced Materials  Philip Rose  Tires  XG Sciences 

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Successful Share Purchase Plan Closes

Posted By Graphene Council, Wednesday, December 11, 2019
Advanced battery anode materials and graphene additives provider Talga Resources is pleased to advise its Share Purchase Plan (“SPP”) closed on Friday, 6 December 2019 after attracting strong participation, with demand for the SPP well in excess of the funds initially sought to be raised.

Talga has received applications under the SPP in excess of A$6.0 million. The Company had previously announced it was targeting A$3.0 million under the SPP, with the Talga Board having discretion to accept oversubscriptions above this limit.

In response to the strong shareholder support the Talga Board has decided that all eligible shareholders who applied for shares under the SPP will receive their full allocation of shares in accordance with the SPP terms and conditions.

The additional capital, beyond the initial target of A$3.0 million, will be used to enhance Talga’s financial flexibility as the Company progresses its short- and medium-term plans, including scaleup of Talnode®-C production for customer qualifications.

Talga Non-executive Chairman, Mr Terry Stinson: “Our aim with the Share Purchase Plan was to provide existing shareholders the opportunity to increase their holdings on the same terms as the recently completed institutional placement - with proceeds used towards funding the last stage of development prior to planned project funding for the Vittangi Graphite Anode Project.

The success of the SPP clearly demonstrates the continued strong support from our shareholders as we progress the execution of our vertically integrated battery anode and graphene additives business strategies. On behalf of the Company, I would like to thank shareholders for their continued support.”

In accordance with the SPP terms, the issue price of the new shares will be A$0.44 per share, being the same price as the issue of shares under the recently completed institutional placement (ASX:TLG 15 Nov 2019 and 21 Nov 2019).

The Company is working with its share registry Security Transfer Australia Pty Ltd to finalise the review of the SPP applications. New fully paid ordinary shares are expected to be issued to eligible applicants under the SPP on Friday, 13 December 2019, once processing of applications has been finalised.

Tags:  Graphene  Graphite  Talga Resources  Terry Stinson 

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Converting graphene into diamond film without high pressure

Posted By Graphene Council, Wednesday, December 11, 2019
Can two layers of graphene be linked and converted to the thinnest diamond-like material? Researchers of the Center for Multidimensional Carbon Materials (CMCM) within the Institute for Basic Science (IBS, South Korea) have reported in Nature Nanotechnology ("Chemically Induced Transformation of CVD-Grown Bilayer Graphene into Fluorinated Single Layer Diamond") the first experimental observation of a chemically induced conversion of large-area bilayer graphene to the thinnest possible diamond-like material, under moderate pressure and temperature conditions.

This flexible, strong material is a wide-band gap semiconductor, and thus has potential for industrial applications in nano-optics, nanoelectronics, and can serve as a promising platform for micro- and nano-electromechanical systems.

Diamond, pencil lead, and graphene are made by the same building blocks: carbon atoms (C). Yet, it is the bonds’ configuration between these atoms that makes all the difference. In a diamond, the carbon atoms are strongly bonded in all directions and create an extremely hard material with extraordinary electrical, thermal, optical and chemical properties. In pencil lead, carbon atoms are arranged as a pile of sheets and each sheet is graphene. Strong carbon-carbon (C-C) bonds make up graphene, but weak bonds between the sheets are easily broken and in part explain why the pencil lead is soft. Creating interlayer bonding between graphene layers forms a 2D material, similar to thin diamond films, known as diamane, with many superior characteristics.

Previous attempts to transform bilayer or multilayer graphene into diamane relied on the addition of hydrogen atoms, or high pressure. In the former, the chemical structure and bonds’ configuration are difficult to control and characterize. In the latter, the release of the pressure makes the sample revert back to graphene. Natural diamonds are also forged at high temperature and pressure, deep inside the Earth. However, IBS-CMCM scientists tried a different winning approach.

The team devised a new strategy to promote the formation of diamane, by exposing bilayer graphene to fluorine (F), instead of hydrogen. They used vapors of xenon difluoride (XeF2) as the source of F, and no high pressure was needed. The result is an ultra-thin diamond-like material, namely fluorinated diamond monolayer: F-diamane, with interlayer bonds and F outside.

For a more detailed description; the F-diamane synthesis was achieved by fluorinating large area bilayer graphene on single crystal metal (CuNi(111) alloy) foil, on which the needed type of bilayer graphene was grown via chemical vapor deposition (CVD).

Conveniently, C-F bonds can be easily characterized and distinguished from C-C bonds. The team analyzed the sample after 12, 6, and 2-3 hours of fluorination. Based on the extensive spectroscopic studies and also transmission electron microscopy, the researchers were able to unequivocally show that the addition of fluorine on bilayer graphene under certain well-defined and reproducible conditions results in the formation of F-diamane. For example, the interlayer space between two graphene sheets is 3.34 angstroms, but is reduced to 1.93-2.18 angstroms when the interlayer bonds are formed, as also predicted by the theoretical studies.

“This simple fluorination method works at near-room temperature and under low pressure without the use of plasma or any gas activation mechanisms, hence reduces the possibility of creating defects,” points out Pavel V. Bakharev, the first author and co-corresponding author.

Moreover, the F-diamane film could be freely suspended. “We found that we could obtain a free-standing monolayer diamond by transferring F-diamane from the CuNi(111) substrate to a transmission electron microscope grid, followed by another round of mild fluorination,” says Ming Huang, one of the first authors.

Rodney S. Ruoff, CMCM director and professor at the Ulsan National Institute of Science and Technology (UNIST) notes that this work might spawn worldwide interest in diamanes, the thinnest diamond-like films, whose electronic and mechanical properties can be tuned by altering the surface termination using nanopatterning and/or substitution reaction techniques. He further notes that such diamane films might also eventually provide a route to very large area single crystal diamond films.

Tags:  2D material  bilayer graphene  Center for Multidimensional Carbon Materials  chemical vapor deposition  Graphene  Institute for Basic Science  Ming Huang  nanoelectronics  Nature Nanotechnology  Pavel V. Bakharev  Rodney S. Ruoff  semiconductor  Ulsan National Institute of Science and Technology 

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How to induce magnetism in graphene

Posted By Graphene Council, Wednesday, December 11, 2019
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example, they may exhibit conducting, semiconducting or insulating behavior. However, one property has so far been elusive: magnetism. Together with colleagues from the Technical University in Dresden, Aalto University in Finland, Max Planck Institute for Polymer Research in Mainz and University of Bern, Empa researchers have now succeeded in building a nanographene with magnetic properties that could be a decisive component for spin-based electronics functioning at room temperature.

Graphene consists only of carbon atoms, but magnetism is a property hardly associated with carbon. So how is it possible for carbon nanomaterials to exhibit magnetism? To understand this, we need to take a trip into the world of chemistry and atomic physics. The carbon atoms in graphene are arranged in a honeycomb structure. Each carbon atom has three neighbors, with which it forms alternating single or double bonds. In a single bond, one electron from each atom – a so-called valence electron – binds with its neighbor; while in a double bond, two electrons from each atom participate. This alternating single and double bond representation of organic compounds is known as the Kekulé structure, named after the German chemist August Kekule who first proposed this representation for one of the simplest organic compound, benzene (Figure 1). The rule here is that electron pairs inhabiting the same orbital must differ in their direction of rotation – the so-called spin – a consequence of the quantum mechanical Pauli’s exclusion principle.

"However, in certain structures made of hexagons, one can never draw alternating single and double bond patterns that satisfy the bonding requirements of every carbon atom. As a consequence, in such structures, one or more electrons are forced to remain unpaired and cannot form a bond," explains Shantanu Mishra, who is researching novel nanographenes in the Empa nanotech@surfaces laboratory headed by Roman Fasel. This phenomenon of involuntary unpairing of electrons is called "topological frustration". But what does this have to do with magnetism?

The answer lies in the "spins" of the electrons. The rotation of an electron around its own axis causes a tiny magnetic field, a magnetic moment. If, as usual, there are two electrons with opposite spins in an orbital of an atom, these magnetic fields cancel each other. If, however, an electron is alone in its orbital, the magnetic moment remains – and a measurable magnetic field results. This alone is fascinating. But in order to be able to use the spin of the electrons as circuit elements, one more step is needed. One answer could be a structure that looks like a bow tie under a scanning tunneling microscope. Two frustrated electrons in one molecule Back in the 1970s, the Czech chemist Erich Clar, a distinguished expert in the field of nanographene chemistry, predicted a bow tie-like structure known as "Clar's goblet" (Figure 1). It consists of two symmetrical halves and is constructed in such a way that one electron in each of the halves must remain topologically frustrated. However, since the two electrons are connected via the structure, they are antiferromagnetically coupled – that is, their spins necessarily orient in opposite directions. In its antiferromagnetic state, Clar's goblet could act as a "NOT" logic gate: if the direction of the spin at the input is reversed, the output spin must also be forced to rotate.

However, it is also possible to bring the structure into a ferromagnetic state, where both spins orient along the same direction. To do this, the structure must be excited with a certain energy, the so-called exchange coupling energy, so that one of the electrons reverses its spin. In order for the gate to remain stable in its antiferromagnetic state, however, it must not spontaneously switch to the ferromagnetic state. For this to be possible, the exchange coupling energy must be higher than the energy dissipation when the gate is operated at room temperature. This is a central prerequisite for ensuring that a future spintronic circuit based on nanographenes can function faultlessly at room temperature. From theory to reality So far, however, room-temperature stable magnetic carbon nanostructures have only been theoretical constructs. For the first time, the researchers have now succeeded in producing such a structure in practice, and showed that the theory does correspond to reality. "Realizing the structure is demanding, since Clar's goblet is highly reactive, and the synthesis is complex," explains Mishra. Starting from a precursor molecule, the researchers were able to realize Clar’s goblet in ultrahigh vacuum on a gold surface, and experimentally demonstrate that the molecule has exactly the predicted properties.

Importantly, they were able to show that the exchange coupling energy in Clar’s goblet is relatively high at 23 meV (Figure 2), implying that spin-based logic operations could therefore be stable at room temperature. "This is a small but important step toward spintronics," says Roman Fasel. Spintronics Spintronics – composed of the words "spin" and "electronics" is a field of research in nanotechnology. The aim is to create electronics in which information is not coded with the electrical charge of electrons, as is the case in conventional semiconductor circuits, but with their magnetic moment caused by the rotation of the electron ("spin"). The electron spin is a quantum mechanical property – a single electron can have not only a fixed state "spin up" or "spin down", but a quantum mechanical superposition of these two states. In the future, spintronics could therefore not only enable further miniaturization of electronic circuits, but could also make electrical switching elements with completely new, previously unknown properties a reality.

Tags:  Aalto University  August Kekule  Graphene  Journal Nature Nanotechnology  magnetism  Max Planck Institute for Polymer Research  nanographene  nanotechnology  Technical University  University of Bern 

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ZEN Graphene Solutions Announces Offering of Flow-Through Shares

Posted By Graphene Council, Wednesday, December 11, 2019
ZEN Graphene Solutions announces that subject to TSX Venture Exchange acceptance, it has arranged an offering of flow-through common shares of the company on a non-brokered private placement basis. The offering comprises up to 2.5 million flow-through common shares of the company at a price of 40 cents per flow-through common share for gross proceeds of up to $1-million. The proceeds from the offering will be used to continue work on the environmental assessment and for community engagement.

All securities issued to purchasers under the offering will be subject to a four-month hold period from the closing date of the offering, pursuant to applicable securities legislation and policies of the exchange. Finders' fees may be paid, as permitted by exchange policies and applicable securities law.

ZEN hires Alphabet Creative

ZEN has hired Alphabet Creative for web services including building its webstore on the Shopify global platform to deliver an exceptional customer experience when they purchase graphene products from the company. Under the agreement, ZEN will issue shares for debt in the sum of $17,000 at a deemed value of $0.36 per share.

Tags:  Graphene  ZEN Graphene Solutions 

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