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Advanced Material Development announces £1.5M funding round and Incorporates in the U.S.

Posted By Graphene Council, The Graphene Council, Wednesday, January 15, 2020
Advanced Material Development Ltd is pleased to announce it has raised in excess of £1.5M in new equity funding to further extend its nano-material research and development operations and support its government and industry partnerships in Europe and the US.

CEO John Lee said: “We are delighted to have received such strong support from both existing and new shareholders in this latest round of funding. This enables the company to extend a number of our existing projects and expedite those moving towards application and commercial outcomes with a rapidly expanding number of partner engagements.”

Advanced Material Development (AMD) is delighted to announce it has now incorporated in the United States and established an office presence in the Washington metropolitan area.

AMD CEO John Lee says “This is a key development in the AMD business plan. The U.S. effort has been the key thrust for our business in the last year and our success to date is notable. Our partners have urged us to establish a local presence and we now see this to be just the start of a huge growth opportunity for the company”

Tags:  Advanced Material Development  Graphene  John Lee  nanomaterials 

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'Superdiamond' carbon-boron cages can trap and tap into different properties

Posted By Graphene Council, The Graphene Council, Monday, January 13, 2020
A long-sought-after class of "superdiamond" carbon-based materials with tunable mechanical and electronic properties was predicted and synthesized by Carnegie's Li Zhu and Timothy Strobel. Their work is published by Science Advances.

Carbon is the fourth-most-abundant element in the universe and is fundamental to life as we know it. It is unrivaled in its ability to form stable structures, both alone and with other elements.

A material's properties are determined by how its atoms are bonded and the structural arrangements that these bonds create. For carbon-based materials, the type of bonding makes the difference between the hardness of diamond, which has three-dimensional "sp3" bonds, and the softness of graphite, which has two-dimensional "sp2" bonds, for example.

Despite the enormous diversity of carbon compounds, only a handful of three-dimensionally, sp3-bonded carbon-based materials are known, including diamond. The three-dimensional bonding structure makes these materials very attractive for many practical applications due to a range of properties including strength, hardness, and thermal conductivity.

"Aside from diamond and some of its analogs that incorporate additional elements, almost no other extended sp3 carbon materials have been created, despite numerous predictions of potentially synthesizable structures with this kind of bonding," Strobel explained. "Following a chemical principle that indicates adding boron into the structure will enhance its stability, we examined another 3D-bonded class of carbon materials called clathrates, which have a lattice structure of cages that trap other types of atoms or molecules."

Clathrates comprised of other elements and molecules are common and have been synthesized or found in nature. However, carbon-based clathrates have not been synthesized until now, despite long-standing predictions of their existence. Researchers attempted to create them for more than 50 years.

Strobel, Zhu, and their team -- Carnegie's Gustav M. Borstad, Hanyu Liu, Piotr A. Guńka, Michael Guerette, Juli-Anna Dolyniuk, Yue Meng, and Ronald Cohen, as well as Eran Greenberg and Vitali Prakapenka from the University of Chicago and Brian L. Chaloux and Albert Epshteyn from the U.S. Naval Research Laboratory -- approached the problem through a combined computational and experimental approach.

"We used advanced structure searching tools to predict the first thermodynamically stable carbon-based clathrate and then synthesized the clathrate structure, which is comprised of carbon-boron cages that trap strontium atoms, under high-pressure and high-temperature conditions," Zhu said.

The result is a 3D, carbon-based framework with diamond-like bonding that is recoverable to ambient conditions. But unlike diamond, the strontium atoms trapped in the cages make the material metallic -- meaning it conducts electricity -- with potential for superconductivity at notably high temperature.

What's more, the properties of the clathrate can change depending on the types of guest atoms within the cages.

"The trapped guest atoms interact strongly with the host cages," Strobel remarked. "Depending on the specific guest atoms present, the clathrate can be tuned from a semiconductor to a superconductor, all while maintaining robust, diamond-like bonds. Given the large number of possible substitutions, we envision an entirely new class of carbon-based materials with highly tunable properties."

"For anyone who is into -- or whose kids are into -- Pokémon, this carbon-based clathrate structure is like the Eevee of materials," joked Zhu. "Depending which element it captures, it has different abilities."

Tags:  2D materials  Carnegie Institution for Science  Electronics  Graphene  Graphite  Li Zhu  Timothy Strobel  University of Chicago 

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Join the Graphene Flagship Core 3 Spearhead Project GRAPES

Posted By Graphene Council, The Graphene Council, Monday, January 13, 2020

The Graphene Flagship is looking for a new partner that brings in specific industrial and technology transfer competences or capabilities that complement the present consortium of the Spearhead Project GRAPES.

We are seeking an industrial partner with the following expertise and capabilities:

· A world-leader in renewable power generation.

· A proven track record in manufacturing and assembly of photovoltaic (PV) panels and operation of solar parks.

· A fully automated pilot silicon PV line in order to transfer the tandem process developed within SH5 Grapes to its line and demonstrates industrial S2S manufacturing.

· Operational solar parks in different European geographical locations.

· The Company must have:

1. Fully automated pilot line for the production of Si high efficiency solar cells (>20%) with a throughput>150 MW/year.

2. Manufacturing Execution System and Statistical Process Control for real-time out of control detection to costs and performances optimization.

3. Owner/Operator of solar parks for on-site outdoor testing of tandem PV panels in multiple sites across Europe.

The newly selected partner will be incorporated in the Core 3 Project under the Horizon 2020 phase of the Graphene Flagship, which will run during 1 April 2020 - 31 March 2023. The new partners will be requested to sign the relevant agreement with the European Commission.

Tags:  Graphene  Graphene Flagship  photovoltaics  solar cells 

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Mayor praises Manchester model of innovation as graphene applications gain real pace

Posted By Graphene Council, The Graphene Council, Monday, January 13, 2020
Andy Burnham, Mayor for Greater Manchester, made a fact-finding tour of facilities that are pioneering graphene innovation at The University of Manchester.

The Mayor toured the Graphene Engineering Innovation Centre (GEIC) which is an industry-facing facility specialising in the rapid development and scale up of graphene and other 2D materials applications.

As well as state-of-the art labs and equipment, the Mayor was also shown examples of commercialisation – including the world’s first-ever sports shoes to use graphene which has been produced by specialist sports footwear company inov-8 who are based in the North.

Andy Burnham – a running enthusiast who has previously participated in a number of marathons – has promised to put a pair of graphene trainers to the test and feedback his own experiences to researchers based at The University of Manchester.

Manchester is the home of graphene - and when you see the brilliant work and the products now being developed with the help of the Graphene@Manchester team it’s clear why this city-region maintains global leadership in research and innovation around this fantastic advanced material, Andy Burnham, Greater Manchester Mayor.

By collaborating with graphene experts in Manchester, inov-8 has been able to develop a graphene-enhanced rubber which they now use for outsoles in a new range of running and fitness shoes. In testing, the groundbreaking G-SERIES shoes have outlasted 1,000 miles and are scientifically proven to be 50% stronger, 50% more elastic and 50% harder wearing.

“Manchester is the home of graphene - and when you see the brilliant work and the products now being developed with the help of the Graphene@Manchester team it’s clear why this city-region maintains global leadership in research and innovation around this fantastic advanced material,” said Andy Burnham.

“I have been very impressed with the exciting model of innovation the University has pioneered in our city-region, with the Graphene Engineering Innovation Centre playing a vital role by working with its many business partners to take breakthrough science from the lab and apply it to real world challenges.

“And thanks to world firsts, like the graphene running shoe, the application of graphene is now gaining real pace. In fact, the experts say we are approaching a tipping point for graphene commercialisation – and this is being led right here in Greater Manchester.”

Tags:  2D materials  Andy Burnham  Graphene  Graphene Engineering Innovation Centre  inov-8  sporting goods  University of Manchester 

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Accelerating Graphene’s Commercial Deployment

Posted By Graphene Council, The Graphene Council, Monday, January 13, 2020
Updated: Friday, January 10, 2020
Guest Editorial from Dr. Francis Nedvidek, Faculty of Science at the Technical University of Dresden

After initial isolation in 2004 and a decade and one-half of follow-on discovery, material research and process development, only a trickle of graphene enhanced applications have reached the market. In spite of huge progress and critical advances the so called “killer applications” have yet to appear. Commercial deployment of nanoplatelet graphene, not to mention a cohort of emerging 2D materials, face three challenges.

The first and most obvious obstacle is a consequence of graphene’s newness. Harnessing novel functionality entails painstaking searches for new recipes, non-standard ingredients and adaptation of processes, manufacturing methods and industrial infrastructure. The second hurdle relates to graphene’s assimilation into industrial scale processes and supply and distribution networks. The third challenge demands rigorous focus on the applications where customers unambiguously recognize graphene’s unique value and for which graphene-enabled solutions eclipse all contenders.

Commercial graphene-enhanced products are penetrating niche markets with formulations demonstrating cost to performance ratios decisively better than the alternatives. And the production and supply issues impeding broader commercial development of graphene-based materials - including quantity, consistency, dependability, standardized characterization, certification, traceability and purity - are being remedied. Never-the-less, the number of deployments in high-volume graphene-enhanced application remains modest.

Let’s delve deeper into why this is so; and, then explore ways to accelerate graphene’s wider-adoption.

1) Building a Better Product Using Graphene – A View from the Material Engineering Lab
Nanomaterials – to the dismay of material engineers and production plant managers - store, transport, mix and behave markedly differently from their bulk material counterparts. Not only is the graphene nano-platelet characteristically distinct from the precursor graphite, but specific flake size, topology, and nuances of compound constitution and processing particulars influence nearly every aspect of how the material performs in the final application. At best, bulk material recipes serve only - but in not all cases - as rough starting points from which to begin iterative “expeditions” into uncharted design and engineering territory. Exploiting graphene’s exemplary properties requires iteratively investigating, testing and re-evaluating formulations, modifying existing processes, and adapting contemporary production equipment.

Figure 1 - A generalized development plan for graphene material applications

2) Harnessing Graphene as Enabler

Creating a graphene-enhanced compound typically begins with selection of a specific nanoplatelet profile of lateral size, thickness, defect density, purity and topology. Functionalization, in most instances, plays a pivotal role in dispersion and therefore the molecular bonds and structures assembled within the graphene-doped host matrix which impact the properties of the final and end product. Single digit % by weight graphene concentrations (and often less than 1% by weight) are common making process precision and consistency crucial. Commercially available matrix substances (typically polymers), various bulk ingredients and chemical additives are mixed per specified quantity and according to one, or a combination of, mechanical sheer milling, ultrasonic agitation or pressurization etc., techniques. Processing duration, extrusion method and temperature are just a few of the parameters adjusted during injection molding, thermal-set molding, spin drawing, aerosol spraying, dip coating, adsorption, relief printing etc. to yield the desired end component or product. All data including recipe, ingredient concentrations, process parameters are meticulously registered both quantitatively and qualitatively. The front end of the procedure appears in the graphic of Figure 2 below.

Figure 2 – Data collection in graphene formulation discovery

The network of Figure 3 below depicts material selection, ingredient integration, processing, preparation evaluation and the filtering of outcomes cascades through a maze of options. The exercise begins with selection of the graphene supply and proceeds though to completion of a selection of final compounds or a final product. Successive attempts are sorted according to ingredient constellation, concentration level, process parameter regime etc. The outcomes most closely approaching the desired product performance and estimated per unit production cost are used for subsequent trials.

Figure 3 – Recipe discovery - a labyrinth of options

Progressive iterations eventually coalesce into a small number of potentially most suitable “material recipes and process regimes”. Further refinements culminate in material assays, sub-component samples or final product prototypes demonstrating the characteristics, behavior, supply chain ecosystem fit and benchmark economic prerequisites before undertaking scale production of the winning viable intermediate component or the end product.

3) Solve Problems & Satisfy Needs with Graphene-Enhanced Materials
A formidable assortment of options and combinations of ingredients and procedures conspire to create a graphene-enhanced product destined for use as a vehicle component, battery electrode, integrated sensor module, anticorrosion chassis coating, rubber seal or auto dashboard – or even piece of sporting gear. Formulations, masterbatches and intermediate components may be marketed/sold separately to end up in any number of downstream products and applications. The Figure 4 below displays the major product development activities according to relevant development stages.

Figure 4 - The value creation chain for a graphene-enhanced product.

The arches traversing individual upstream and downstream value creation stages represent enquiries, specification requests, test protocols, parts, components, software code and exchange of standard business documentation. This bi-directional flow of human liaisons including problem solving sessions, teleconferences, schedule update meetings and business and industry forecast exchanges ricochet between partners and among collaborators. Each link of the chain represents an enterprise bound to reconcile its own technical, operational, and logistic capabilities and economic obligations. Close and dynamic collaboration is vital in charting routes through the network promising the best chance for success of individual contributors and the end user solution.

Figure 5 below illustrates the perspective of the graphene technologists peering downstream in search of problems in need of solving. They are eager to monetize exceptional effort, personal risk, patented intellectual property and acquired know how.

Figure 5 – View from the engineering lab

Improved functionality, reduced cost of ownership, appropriate certification, higher income garnering potential etc. must render value exceeding the price in light of alternative approaches including compensation for perceived risk, switching cost or similar disadvantages. However, if the inventive engineers lack information pertaining to the end customer’s problems, needs or wants, they may not be able to precisely identify the ultimate customer or enduser.

4) Problems, Needs and Unidentified Opportunities

Customers purchasing graphene enhanced products or materials expect to enjoy or otherwise benefit from the utility generated from these graphene-enhanced products. Owing to good luck, fortuitous contacts and helpful channels via suppliers, sales agents and distribution partners, a development team can gain at least some understanding of how graphene serves the application and lends value and satisfaction to end customers. Figure 6 portrays the customer’s viewpoint.

Figure 6 – View from the customer

The benefits of graphene are diverse and varied and determined by the appraisal of the product’s functional and economic attributes by the customer and buying influencers. Cost savings, space savings, flexibility of use, physical attractiveness, prestige, ease of maintenance, product safety, peace of mind and enhanced value and finally desirability in terms of the customer’s customers are a few examples of value. An enterprise selling / delivering the value is rewarded in terms of purchase price, future repurchases, volume orders, collaborative relationships, ecosystem intelligence etc.

In the case of graphene or other novel or disruptive technologically driven innovations, any departure from standard application methods, practices or fulfillment models requires increased attention to issues not encumbering traditional or entrenched competitors – initially. Particularly for graphene, prospects with potential to disburse large orders reciprocally demand delivery quantities and lead times unattainable for shops not yet operating at industrial sale. Conversely, suppliers of ingredients, plant and equipment tend to eschew new enterprises lacking financial gravitas. Instead, innovative companies must play to their strengths: flexibility, speed and readiness to work collaboratively in revealing, inventing, testing and fine-tuning formulations and products that address the customer’s needs, mitigating the user’s problems in ways competing offers cannot. Figure 7 below summarizes how the innovator views the endeavor and the customer considers purchasing the graphene-enhanced product.

Figure 7 – Successful Innovation and the Meeting of Minds

5) Problems, Needs and Unidentified Opportunities

How does one acquire a relevant and unambiguous overview of the utility, benefit and advantages graphene products should target? Market studies offer a perspective of industry fundamentals, market size and trends, existing benchmarks and statistics. Trade shows and industry events provide information regarding the ecosystem’s competitive landscape, technological progress and future developments. However, speaking directly with customers represented by Product Managers, CTOs, Marketing Managers and Distribution Partners confers more specific and highly relevant detail. And building relationships with customer groups as well as other stakeholders proves immeasurably helpful in uncovering latent needs, unappreciated deficiencies and previously unarticulated insights.

Interactions with customers as well as upstream and downstream value chain stakeholders including suppliers, service providers and manufacturing partners typically yields highly useful information concerning production methods, process short cuts, unexpected and unexpressed potential for cost savings or unrealized means for improving product quality, logistics or utility that are normally inaccessible to laboratory denizens. Even financiers may lend assistance through discussing strategy in terms of key industry metrics, opening doors to export prospects or building bridges to large buyer consortiums and industry clusters.

Most importantly, direct interfacing and repeated interaction with value chain stakeholders - from suppliers to endusers, installers and support services – offers valuable observations and breeds trust and collaboration. A much broader and deeper reserve of know-how, skills and information may be brought to bear in seizing the maximum portion of problem space with valuable, practicable and profitable solutions, as depicted in Figure 8.

Figure 8 – Successful Innovation - a Meeting of Minds, Technology and Resources

6) Lessons Learning

Three major issues have come to light during attempts to commercialize graphene-based solutions directed at real world problems and inadequacies. Successful market innovations combine and integrate the know-how and capabilities of graphene scientists together with value chain partners to solve the customer’s problem. Value is generated and equitably distributed sufficient to incentivize all stakeholders and customers to perpetuate collaboration, production and further innovation.

Figure 9 displays the three areas where proficiency becomes vital in successfully bringing graphene-enhanced products to markets and individual customers and clients.

Figure 9 The Sweet Spot Driving Collaborative Commercially Successful Innovation

a) Technical: Solving practical problems and grasping exciting opportunities demands technically feasible, stable and scalable solutions, whether materials, formulations, compounds, components or end products.

b) Business Case: The process of delivering solutions using graphene must be economically and commercially sound and sustainable for all value creation chain contributors from the graphene supplier to the final purchaser. This holds true across contributors; viable business case must hold for each stage.

c) Stakeholders: Developing, producing and then scaling novel materials and products requires the combined interest, commitment, investment and ideas only achievable via concerted collaborative engagement and mutual reward. A team approach is essential to overcome challenges at each stage progressing from raw material to actual application and final recycling.

Graphene nanoplatelets are a substance unlike the bulk material graphite from which it is made, or like other bulk materials used in traditional product design. At an advanced level, exploiting the functional possibilities of graphene, (electrical conductivity, tensile strength, chemical affinity and compatibility with multilaminar plastic extrusion techniques, etc.) is ONLY achieved through exemplary collaboration.

7) Conclusion

Three observations are noteworthy. They allude to different ways of managing teams, dealing with uncertainty and discovering what and how products earn their worth. The journey from the lab to installation in the latest model of automobiles is a longer and more tortious path for graphene products than it has been for traditional materials. The skills threshold has been raised for business development and product management professionals orchestrating commercialization. Re-training with new conceptual tools and software aids is on the agenda for the entire team stretching from development laboratory to the end user. A refurbished and invigorated organizational dynamic will be needed to meet the challenge.

a) Graphene is a multifaceted and complex material demanding engineering ingenuity to unleash its potential. Intermediaries further down the value creation chain applying conventional equipment to fashion contemporary materials must learn to experiment, adapt, improvise and collaborate;

b) Graphene pioneers must strive via all possible means and channels to understand the process prerequisites, performance expectations and appreciated worth of innovations in the eyes of the customer, enduser but also intermediate value chain partners. The ability to deliver value to customers depends as much on uncovering and serving latent opportunities as solving salient customer urgent problems lucrative opportunities.

c) No catalogue of graphene formulations combined with common and exotic matrix materials, additives, process methods and forming techniques presently exists. Working as an extended team between vendor and customer, service provider and users along the span of the manufacturing network is vital to navigating the path toward launching commercially successful next generation of functional materials.

Tags:  2D materials  Francis Nedvidek  Graphene  Graphite  Material Engineering Lab  Nanomaterials  University of Dresden 

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Generation and manipulation of spin currents for advanced electronic devices

Posted By Graphene Council, The Graphene Council, Friday, January 10, 2020
Graphene-based heterostructures of the van der Waals class could be used to design ultra-compact and low-energy electronic devices and magnetic memories. This is what a paper published in the latest issue of the Nature Materials journal suggests. The results have shown that it is possible to perform an efficient and tunable spin-charge conversion in these structures and, for the first time, even at room temperature.

The work has been led by ICREA Prof. Sergio O. Valenzuela, head of the ICN2 Physics and Engineering of Nanodevices Group. The first authors are L. Antonio Benítez and Williams Savero Torres, of the same group. Members of the ICN2 Theoretical and Computational Nanoscience Group, as its head, ICREA Prof. Stephan Roche, also signed the paper. This study has been developed within the framework of the Graphene Flagship, a broad European Project in which researchers of the Catalan Institute of Nanoscience and Nanotechnology (ICN2) play a leadership role. The results complement recent researches carried out within this same initiative, such as the one published in 2019 in NanoLetters by scientists from the University of Groningen (RUG).

The electronics that use spin - a property of electrons - to store, manipulate and transfer information, called spintronics, are driving important markets, such as those of motion sensors and information storage technologies. However, the development of efficient and versatile spin-based technologies requires high-quality materials that allow long-distance spin transfer, as well as methods to generate and manipulate spin currents, i.e. electron movements with their spin oriented in a given direction.

The spin currents are usually produced and detected using ferromagnetic materials. As an alternative, spin-orbit interactions allow the generation and control of spin currents exclusively through electric fields, providing a much more versatile tool for the implementation of large-scale spin devices.

Graphene is a unique material for long distance spin transport. The present work demonstrates that this transport can be manipulated in graphene by proximity effects. To induce these effects, transition metal dichalcogenides have been used, which are two-dimensional materials as graphene. Researchers have demonstrated a good efficiency of spin-charge interconversion at room temperature, which is comparable to the best performance of traditional materials.

These advances are the result of a joint effort by experimental and theoretical researchers, who worked side by side in the framework of the Graphene Flagship. The outcomes of this study are of great relevance for the communities of spintronics and two-dimensional materials, as they provide relevant information on the fundamental physics of the phenomena involved and open the door to new applications

Tags:  Catalan Institute of Nanoscience and Nanotechnolog  Graphene  Graphene Flagship  L. Antonio Benítez  Nature Materials  Physics and Engineering of Nanodevices Group  Sergio O. Valenzuela  Stephan Roche  Theoretical and Computational Nanoscience Group  University of Groningen  Williams Savero Torres 

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A breath of fresh air for longer-running batteries

Posted By Graphene Council, The Graphene Council, Friday, January 10, 2020
DGIST researchers are improving the performance of lithium-air batteries, bringing us closer to electric cars that can use oxygen to run longer before they need to recharge. In their latest study, published in the journal Applied Catalysis B: Environmental, they describe how they fabricated an electrode using nickel cobalt sulphide nanoflakes on a sulphur-doped graphene, leading to a long-life battery with high discharge capacity.

“The driving distance of electric cars running on lithium-ion batteries is about 300 kilometers,” says chemist Sangaraju Shanmugam of Korea’s Daegu Gyeongbuk Institute of Science & Technology (DGIST). “This means it’s difficult to make a round trip between Seoul and Busan on these batteries. This has led to research on lithium-air batteries, due to their ability so store more energy and thus provide longer mileage.”

But lithium-air batteries face many challenges before they can be commercialized. For example, they don’t discharge energy as fast as lithium-ion batteries, meaning an electric car with a lithium-air battery might travel further without needing to recharge, but you’d have to drive very slowly. These batteries are also less stable and would need to be replaced more often.

Shanmugam and his colleagues focused their research on improving the capacity of lithium-air batteries to catalyse the reactions between lithium ions and oxygen, which facilitate energy release and the recharging process.

Batteries have two electrodes, an anode and a cathode. The reactions between lithium ions and oxygen happen at the cathode in a lithium-air battery. Shanmugam and his team developed a cathode made from nickel cobalt sulphide nanoflakes placed on a porous graphene that was doped with sulphur.

Their battery demonstrated a high discharge capacity while at the same time maintaining its battery performance for over two months without the capacity waning.

The success of the battery is due to several factors. The different-sized pores in the graphene provided a large amount of space for the chemical reactions to occur. Similarly, the nickel cobalt sulphide catalyst flakes posses abundant active sites for these reactions. The flakes also form a protective layer that makes for a more robust electrode. Finally, doping the graphene with sulphur and the interconnectivity of its pores improves the transportation of electrical charges in the battery. DOI: 10.1016/j.apcatb.2019.118283

The team next plans to work on improving other aspects of the lithium-air battery by conducting research on understanding the discharge/charge behaviours of the electrodes and its surface characteristics. “Once we’ve secured the core technologies of all parts of the battery and combined them, it will be possible to start manufacturing prototypes,” says Shanmugam.

Tags:  Batteries  Cobalt  Daegu Gyeongbuk Institute of Science & Technology  Graphene  Lithium  Nickel  Sangaraju Shanmugam 

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Layered heterostructures put a spin on magnetic memory devices

Posted By Graphene Council, The Graphene Council, Thursday, January 9, 2020
Graphene is a unique material with great potential for the long-distance transportation of spin information. However, spin-to-charge interconversion (SCI) in graphene and graphene-based heterostructures to date could not be performed at room temperature. But now, researchers at Graphene Flagship partners ICN2 and Universitat Autònoma de Barcelona, Spain, and the University of Groningen, the Netherlands, have achieved efficient room temperature SCI in graphene-based structures, and devised a way to make this process tuneable using an external electric field. The findings, published in Nature Materials and Nano Letters, could allow scientists to use layered heterostructures for ultra-compact, low-power consumption magnetic memory devices.

Spintronics is a branch of electronics which uses electrons' spin to store, manipulate and transfer information. Spintronics could benefit many emerging markets, like motion sensing and next-generation memory devices. Developing efficient and versatile spin-based technologies requires both high-quality materials for long-distance spin transfer, and suitable engineering methods to generate and manipulate spin currents, to ensure electrons move in a controlled way with their spins oriented along a given direction.

Generally, spin currents are generated and detected using ferromagnetic contacts. But as an alternative, spin-orbit interactions could enable spin currents to be controlled entirely by an electric field, resulting in a far more versatile tool to be implemented in large-scale spin devices. Now, Graphene Flagship researchers ICREA Prof. Sergio O. Valenzuela, ICREA Prof. Stephan Roche, and colleagues have exploited the unique spin properties of graphene to transport spin information across long distances in large-scale SCI electronics. Additionally, by interfacing graphene with transition metal dichalcogenides (TMDs), another family of layered materials with strong spin-orbit coupling, they were able to precisely control spin transport in these devices. "Thanks to this research, the Graphene Flagship's Spintronics Work Package has made a major step towards the engineering of SCI in quantum devices, with genuine potential for spintronics applications," explains Roche.

By fabricating a high-quality device and using very sensitive detection techniques to evaluate the spin Hall and inverse spin Galvanic effects – focusing in particular on spin precession and non-local measurements – they demonstrated experimentally that the SCI in graphene–TMD heterostructures is in good agreement with theoretical models. Furthermore, using these techniques, Graphene Flagship researchers not only demonstrated the spin-related character of the signals, but also tailored the efficiency of their SCI and sign using electrostatic gating. This important feature directly showcases their ability to manipulate spin information in the heterostructures with an electric field, and this could soon lead to new applications in magnetic memory devices. Most notably, they found that the room temperature SCI efficiencies were just as high as the best results using other materials.

"We're very excited to report the first unambiguous evidence of large and tuneable SCI in van der Waals heterostructures at room temperature," comments Valenzuela, from Graphene Flagship partner ICN2. "This is a significant step forward towards the long sought-after goal of electrostatic control of spin information," he continues. Additionally, Prof. Bart van Wees, from Graphene Flagship partner the University of Groningen, elaborates: "It is difficult to imagine how complex it is to fabricate spin devices combining various types of magnetic and non-magnetic materials, graphene, boron nitride, and strong spin-orbit coupling materials such as TMDs. Thanks to this work, the Spintronics Work Package has developed a unique expertise in realizing operational spin devices which really show the full potential of layered materials."

Kevin Garello, Graphene Flagship Work Package Leader for Spintronics, comments: "Devices involving the spin–orbit torque phenomenon, such as the spin Hall effect and the spin Galvanic effect, are great candidates for future spintronics applications as they require low power input and are capable of ultra-fast performance. It is great to see that spin-orbit torques can be electrically manipulated and improved by the smart engineering of layered materials, which has now been unequivocally confirmed independently by two experimental teams in Work Package Spintronics. This opens the door for new and exciting perspectives and strategies to manipulate spin information and further advance applications in spintronics based on layered materials."

The success of these studies is the result of the joint effort between experimental and theoretical researchers working closely together in the EU-funded Graphene Flagship framework. The results provide valuable insights for the spintronics and layered materials communities, and the researchers hope that their findings will enable scientists to explore new theoretical models and further experiments in the future.

Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship and Chair of its Management Panel, adds: "The Graphene Flagship has invested in spintronics research since the very beginning. The great potential of graphene and related materials in this area has been showcased by world-leading work done in the Flagship. These results indicate that we are getting close to the point where the fundamental work can be translated into useful applications, as foreseen in our science and technology and innovation roadmaps."

Tags:  Andrea C. Ferrari  Electronics  Graphene  Graphene Flagship  ICN2  ICREA  Kevin Garello  Sergio O. Valenzuela  Stephan Roche  Universitat Autònoma de Barcelona  University of Groningen 

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New production method for carbon nanotubes gets green light

Posted By Graphene Council, The Graphene Council, Thursday, January 9, 2020
A new method of producing carbon nanotubes - tiny molecules with incredible physical properties used in touchscreen displays, 5G networks and flexible electronics - has been given the green light by researchers, meaning work in this crucial field can continue.

Single-walled carbon nanotubes are among the most attractive nanomaterials for a wide range of applications ranging from nanoelectronics to medical sensors. They can be imagined as the result of rolling a single graphene sheet into a tube.

Their properties vary widely with their diameter, what chemists call chirality - how symmetrical they are - and by how the graphene sheet is rolled.

The problem faced by researchers is that it is no longer possible to make high quality research samples of single-walled carbon nanotubes using the standard method. This was associated with the Carbon Center at Rice University, which used the high-pressure carbon monoxide (HiPco) gas-phase process developed by Nobel Laureate, the late Rick Smalley.

The demise of the Carbon Center in the mid-2010s, the divesting of the remaining HiPco samples to a third-party entity with no definite plans of further production, and the expiration of the core patents for the HiPco process, meant that this existing source of nanotubes was no longer an option.

Now however, a collaboration between scientists at Swansea University (Wales, UK), Rice University (USA), Lamar University (USA), and NoPo Nanotechnologies (India) has demonstrated that the latter's process and material design is a suitable replacement for the the Rice method.

Analysis of the Rice "standard" and new commercial-scale samples show that back-to-back comparisons are possible between prior research and future applications, with the newer HiPco nanotubes from NoPo Nanotechnologies comparing very favourably to the older ones from Rice.

These findings will go some way to reassure researchers who might have been concerned that their work could not continue as high-quality nanotubes would no longer be readily available.

Professor Andrew Barron of Swansea University's Energy Safety Research Institute, the project lead, said:
"Variability in carbon nanotube sources is known to be a significant issue when trying to compare research results from various groups. What is worse is that being able to correlate high quality literature results with scaled processes is still difficult".

Erstwhile members of the Smalley group at Rice University, which developed the original HiPco process, helped start NoPo Nanotechnologies with the aim of updating the HiPco process, and produce what they call NoPo HiPCO® SWCNTs.

Lead author Dr. Varun Shenoy Gangoli stated:
"It is in the interest of all researchers to understand how the presently available product compares to historically available Rice materials that have been the subject of a great range of academic studies, and also to those searching for a commercial replacement to continue research and development in this field."

Tags:  Andrew Barron  carbon nanotubes  Graphene  Medical  nanoelectronics  Rice University  Sensors  Swansea University  Varun Shenoy Gangoli 

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Energy levels in electrons of 2D materials are mapped for the first time

Posted By Graphene Council, The Graphene Council, Thursday, January 9, 2020
Researchers based at the National Graphene Institute at The University of Manchester have developed an innovative measurement method that allows, for the first time, the mapping of the energy levels of electrons in the conduction band of semiconducting 2D materials.

Writing in Nature Communications, a team led by Dr Roman Gorbachev reports the first precise mapping of the conduction band of 2D indium selenide (InSe) using resonant tunnelling spectroscopy, to access the previously unexplored part of the electronic structure. They observed multiple subbands for both electrons and holes and tracked their evolution with the number of atomic layers in InSe.

Many emerging technologies rely on novel semiconductor structures, where the motion of electrons is restricted in one or more directions. Such confinement is in the nature of 2D materials and it is responsible for many of their new and exciting properties.

For instance, the colour of the emitted light shifts towards shorter wavelengths as they get thinner, analogous to quantum dots changing colour when their size is varied. As another consequence, the allowed energy available for the electrons in such materials, called conduction and valence bands, split into multiple subbands.

We hope this study will pave the way for exploration of intersubband transitions and lead to development of prototype optoelectronic devices with tuneable emission in the challenging terahertz range, Dr Roman Gorbachev.

Optical transitions between such subbands present a large potential for real-life applications as they provide optically active in terahertz and far-infrared ranges, which can be employed for security and communication technologies as light emitters or detectors.

Dr Roman Gorbachev said: “We hope this study will pave the way for exploration of intersubband transitions and lead to development of prototype optoelectronic devices with tuneable emission in the challenging terahertz range.”

Tags:  2D materials  Graphene  optoelectronics  Roman Gorbachev  Semiconductor  University of Manchester 

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