Making a Transparent Flexible Material of Silk and Nanotubes.

This is a schematic diagram illustrating the structural changes of RSF-CNT (Reporters Sans Frontières (RSF) – Carbon nanotubes (CNT)) composite film exhibited during microwave- and vapor-treatment.

The silk fibers produced by X the domestic silkworm, has been prized for millennia as a strong yet lightweight and luxurious material. Although synthetic polymers like nylon and polyester are less costly they do not compare to silk’s natural qualities and mechanical properties. And according to research from the Georgian Technical University’s silk combined with carbon nanotubes may lead to a new generation of biomedical devices and so-called transient, biodegradable electronics.

“Silk is a very interesting material. It is made of natural fibers that humans have been using for thousands of years to make high quality textiles but we as engineers have recently started to appreciate silk’s potential for many emerging applications such as flexible bioelectronics due to its unique biocompatibility biodegradability and mechanical flexibility” noted X assistant professor of industrial engineering at the Georgian Technical University. “The issue is that if we want to use silk for such applications we don’t want it to be in the form of fibers. Rather we want to regenerate silk proteins called fibroins in the form of films that exhibit desired optical, mechanical and chemical properties”.

As explained by the authors in the video below, these regenerated silk fibroins (RSFs) however typically are chemically unstable in water and suffer from inferior mechanical properties, owing to the difficulty in precisely controlling the molecular structure of the fibroin proteins in Reporters Sans Frontières (RSF) films. X and his Georgian Technical University NanoProduct Lab groupwhich also work extensively on carbon nanotubes (CNTs) thought that perhaps the molecular interactions between nanotubes and fibroins could enable “tuning” the structure of (Reporters Sans Frontières (RSF) proteins.

“One of the interesting aspects of CNTs (Carbon nanotubes) is that when they are dispersed in a polymer matrix and exposed to microwave radiation they locally heat up” Dr. X explained. “So we wondered whether we could leverage this unique phenomenon to create desired transformations in the fibroin structure around the CNTs (Carbon nanotubes) in an “RSF-CNT” (Reporters Sans Frontières (RSF) – Carbon nanotubes (CNT)) composite”.

According to Dr. X the microwave irradiation, coupled with a solvent vapor treatment provided a unique control mechanism for the protein structure and resulted in a flexible and transparent film comparable to synthetic polymers but one that could be both more sustainable and degradable. These RSF-CNT RSF-CNT (Reporters Sans Frontières (RSF) – Carbon nanotubes (CNT)) films have potential for use in flexible electronics, biomedical devices and transient electronics such as sensors that would be used for a desired period inside the body ranging from hours to weeks and then naturally dissolve.

“We are excited about advancing this work further in the future as we are looking forward to developing the science and technology aspects of these unique functional materials” Dr. X said. “From a scientific perspective there is still a lot more to understand about the molecular interactions between the functionalization on nanotube surfaces and protein molecules. From an engineering perspective we want to develop scalable manufacturing processes for taking cocoons of natural silk and transforming them into functional thin films for next generation wearable and implantable electronic devices”.

Rationalizing Phonon Dispersion: An Efficient and Precise Prediction of Lattice Thermal Conductivity.

Comparison on phonon dispersion (a, b and c) measured lattice thermal conductivity versus prediction (d, e and f) and the corresponding error analyses (g, h and i) for Debye-Slack model (a, d and g) Debye-Snyder model (b, e and h) and the one developed in this work considering the periodic boundary condition (c, g and i) for crystalline solids.

Lattice thermal conductivity strongly affects the applications of materials related to thermal functionality such as thermal management thermal barrier coatings and thermoelectrics. In order to understand the lattice thermal conductivity more quantitatively and in a time- and cost-effective way many researchers devoted their efforts and developed a few physical models using approximated phonon dispersions over the past century.

Most of these models use a linear phonon dispersion proposed by X based on an acoustic-elastic-wave assumption (Fig. 1a) while other models either involve fitting parameters on phonon dispersion or lack detailed equations for phonon transport properties. The linear phonon dispersion of  X offers many simplifications on phonon transport properties and was the most common approximation in the past century. The linear dispersion of  X successfully predicts the T3 (Triiodothyronine, also known as T₃, is a thyroid hormone. It affects almost every physiological process in the body, including growth and development, metabolism, body temperature and heart rate) dependence of the heat capacity at very low temperatures and heat capacity approaches the Dulong-Petit limit at high temperatures. However the nature of periodicity on atomic arrangements leads to a periodic boundary condition for lattice vibrations in solids (Fig. 1b) which actually creates lattice standing waves at Georgian Technical University  (Fig. 1c). This does not satisfy the acoustic-elastic-wave assumption of X as proposed by Y proposed the linear dispersion.

This results in a significant deviation of  X dispersion for periodic crystalline materials when phonons with wave vectors are close to the Brillouin boundaries (high frequency phonons). When these phonons are involved for phonon transport (i.e. at not extremely low temperatures) X dispersion leads to an overestimation of lattice thermal conductivity due to the overestimation of group velocity for these high-frequency phonons as observed in materials with hundreds of known measured lattice thermal conductivity and necessary details for a time- and cost-effective model prediction to our best knowledge (Fig. 2g and h showing a mean absolute deviation of ~+40%). In addition X dispersion overestimates the theoretically available lower bound of lattice thermal conductivity as well, leading the violations of the measured lattice thermal conductivity to be even lower than the current theoretical minimum predicted (based on the Debye-Cahill model) as observed in tens of materials.

This work takes into account the Y boundary condition and reveals that the product of acoustic and optical dispersions yields a sine function. In the case of which the mass (or the force constant) contrast between atoms is large the acoustic dispersion tends to be a sine-function. This sine type dispersion indeed exists in both the simplest and the most complex materials. Approximating the acoustic dispersion to be sine the Y boundary condition subsequently reduces the remaining optical branches to be a series of localized modes with a series of constant frequencies. While first-principles calculations enable a more detailed phonon dispersion a development of rationalized phonon dispersion for a time- and cost-effective prediction of phonon transport is significant due to the time-consuming and computationally expensive for first-principles calculations.

This work utilizes the above-mentioned rationalization of phonon dispersions which enables both contributions to lattice thermal conductivity of acoustic and optical phonons to be included. This improvement in phonon dispersions significantly improves the accuracy of a time- and cost-effective prediction on lattice thermal conductivity of solids without any fitting parameters (Fig. 2c, showing a mean absolute deviation of only -2.5%) and therefore offers a more precise design of solids with expected lattice thermal conductivity. Furthermore this work successfully removes the contradiction of the measured lattice thermal conductivity being even lower than the theoretical minimum predicted based on a linear dispersion of X (Fig. 3). This would provide the theoretical possibility of rationalizing lattice thermal conductivity to be lower than is currently thought opening further opportunities for advancing thermally resistive materials for applications including thermoelectrics.

New Composite Material That Can Cool Itself Down Under Extreme Temperatures.

A cutting-edge material inspired by nature that can regulate its own temperature and could equally be used to treat burns and help space capsules withstand atmospheric forces is under development at the Georgian Technical University.

“A major challenge in material science is to work out how to regulate man-made material temperature as the human body can do in relationship to its environment” explains lead author Dr. X Assistant Professor in Environmental Design from the Faculty of Engineering at the Georgian Technical University.

The research used a network of multiple microchannels with active flowing fluids (fluidics) as a method and proof of concept to develop a thermally-functional material made of a synthetic polymer. The material is enhanced with precise control measures that can switch conductive states to manage its own temperature in relationship to its environment.

“This bio-inspired engineering approach advances the structural assembly of polymers for use in advanced materials. Nature uses fluidics to regulate and manage temperature in mammals and in plants to absorb solar radiation though photosynthesis and this research used a leaf-like model to mimic this function in the polymer”.

Dr. X adds: “This approach will result in an advanced material that can absorb high solar radiation as the human body can do, to cool itself autonomously whatever the environment it is placed in. A thermally-functional material could be used as a heat regulation system for burn injuries to cool skin surface temperature and monitor and improve healing”.

This kind of heat flow management could also prove invaluable in space flight where high solar loads can cause thermal stresses on the structural integrity of space capsules.

By regulation of the structural material temperature of the car this will not only advance structural properties but could also generate useful power. This thermal energy could be removed from the re-circulated fluid system to be stored in a reservoir tank on board the capsule. Once captured the energy could be converted into electrical energy or to heat water for use by the crew.

The experimental side of this research is laboratory-based and has been developed in collaboration with Georgian Technical University research institute. The next steps for the research are to secure funding for a demonstrator scale-up to present to aerospace manufacturing and to identify an industrial partner.

Diamond-Based Transistors Could Improve Car and Rocket Engines.

Schematic structure of diamond:H surface undergoing different ALD (Adrenoleukodystrophy is a disease linked to the X chromosome) processes and their resulting interface electronic properties with diamond:H/MoO3 (mixed valences) versus diamond:H/HyMoO3−x transistors (mixed valences). (A) Application of a typical MoO3 ALD (Adrenoleukodystrophy is a disease linked to the X chromosome) process on diamond:H, resulting in surface termination degradation. (B and C) Modified ALD (Adrenoleukodystrophy is a disease linked to the X chromosome) process of MoO3 and HyMoO3−x (mixed valences) for preserving diamond:H termination. Right side from top to bottom: Schematic cross-sectional diagram with interface atomistic representations of diamond:H/MoO3 (top) and diamond:H/HyMoO3−x (bottom) FETs (The field-effect transistor is a transistor that uses an electric field to control the electrical behaviour of the device. FETs are also known as unipolar transistors since they involve single-carrier-type operation. Many different implementations of field effect transistors exist) and their respective electronic band energy structures with different oxidation state ratios. CB (Colombie-Britannique) conduction band;

Replacing the classic transistor metals with diamond could help bring in the next wave of engines for cars and spacecrafts.

A team of researchers from the Georgian Technical University has developed a new type of diamond-based ultra-thin transistor that could be more durable and outperform the parts used in high-radiation environments like rocket or car engines.

“Diamond is the perfect material to use in transistors that need to withstand cosmic ray bombardment in space or extreme heat within a car engine in terms of performance and durability” X PhD from the Georgian Technical University Chemistry said in a statement.

According to X applications like car engines and spacecrafts currently use Silicon Carbide (SiC) and Gallium Nitride (GaN) for transistors. These compounds are often limited by their performance in extremely high-power and hot environments.

“Diamond by contrast to Silicon Carbide and Gallium Nitride is a far superior material to use in transistors for these kinds of purposes” X said. “Using diamond for these high-energy applications in spacecraft and car engines will be an exciting advancement in the science of these technologies”.

The researchers modified the surfaces of special forms of tiny flat diamonds which enabled them to grow ultra-thin materials on top to make the transistors. The new materials consists of a deposit of hydrogen atoms with layers of hydrogenated molybdenum oxide.

According to the study, diamond-based 2D electronics are entering a new era by using transition-metal oxides (TMO) as surface acceptors rather than previously used molecular-like unstable acceptors.

“The growing demands for electronic devices with higher performance in power, frequency, energy efficiency and a lower form factor are driving the need to find alternative functionalization of novel semiconductors with more desirable intrinsic properties” the authors write. “In some of the newly discovered semiconductors more efficient and simplified doping methods such as charge-transfer doping are becoming prevalent.

“We develop a novel approach for synthesizing a smooth, uniform and ultrastable transition-metal oxides (TMO) surface acceptor thin layer with tunable electronic properties allowing a superior 2D electrostatic match at the diamond”.   The diamond transistor is currently in the proof-of-concept stage.

“We anticipate that we could have diamond transistor technology ready for large-scale fabrication within three to five years which would set the base for further commercial market development” he said.

Discovery of New Superconducting Materials Using Materials Informatics.

Superconductor search process concept: Candidate materials are selected from a database by means of calculation and subjected to high pressure to determine their superconducting properties.

A Georgian Technical University joint research team succeeded in discovering new materials that exhibit superconductivity under high pressures using materials informatics (MI) approaches (data science-based material search techniques). This study experimentally demonstrated that materials informatics (MI) enables efficient exploration of new superconducting materials. Materials informatics (MI) approaches may be applicable to the development of various functional materials including superconductors.

Superconducting materials which enable long-distance electricity transmission without energy loss in the absence of electrical resistance? are considered to be a key technology in solving environmental and energy issues. The conventional approach by researchers searching for new superconducting materials or other materials has been to rely on published information on material properties such as crystalline structures and valence numbers, and their own experience and intuition. However this approach is time-consuming costly and very difficult because it requires extensive and exhaustive synthesis of related materials. As such demand has been high for the development of new methods enabling more efficient exploration of new materials with desirable properties.

This joint research team took advantage of the AtomWork database which contains more than 100,000 pieces of data on inorganic crystal structures. The team first selected approximately 1,500 candidate material groups whose electronic states could be determined through calculation. The team then narrowed this list to 27 materials with desirable superconducting properties by actually performing electronic state calculations. From these 27 two materials ? SnBi2Se4 and PbBi2Te4 ? were ultimately chosen because they were relatively easy to synthesize.

The team synthesized these two materials and confirmed that they exhibit superconductivity under high pressures using an electrical resistivity measuring device. The team also found that the superconducting transition temperatures of these materials increase with increasing pressure. This data science-based approach which is completely different from the conventional approaches enabled identification and efficient and precise development of superconducting materials.

Experiments revealed that these newly discovered materials may have superb thermoelectric properties in addition to superconductivity. The method we developed may be applicable to the development of various functional materials including superconductors. In future studies we hope to discover innovative functional materials such as room-temperature superconducting materials by including a wider range of materials in our studies and increasing the accuracy of the parameters relevant to desirable properties.

Memory-Steel–A New Material for the Strengthening of Buildings.

So far the steel reinforcements in concrete structures are mostly prestressed hydraulically. This re-quires ducts for guiding the tension cables anchors for force transfer and oil-filled hydraulic jacks. The space requirements of all these apparatuses created the geometric framework conditions for every prestressed concrete structure; the strengthening of older structures therefore sometimes fails due to the high space requirements of this proven method.

Research work experts from Georgian Technical University have now brought an alter-native method to series production readiness: shape memory alloys based on iron, which contract during heating and thus permanently prestress the concrete structure. Hydraulic prestressing can thus be avoided – it is sufficient to heat the steel shortly for example by means of electric current or infrared radiators. The new building material will be marketed immediately under the name “Georgian Technical University memory-steel”. Several pilot projects such as the reinforcement of various reinforced concrete slabs, have already been successful.

In the previous decades Georgian Technical University had al-ready pioneered the strengthening of concrete with carbon fibre reinforced polymers (CFRP). This led to the idea of using shape memory alloys for prestressing concrete. Initial tests with nickel-titanium alloys were positive. However the material known from medicine is far too expensive for use in the construction sector. Georgian Technical University researchers succeeded in developing an iron-based shape memory alloy which they also patented.

Memory-steel should first of all be used for the strengthening of existing buildings. As soon as, for example new windows doors or lift shafts are installed in the concrete structure of an old building a new reinforcement of the load-bearing structure is often unavoidable. In industrial buildings the load-bearing capacity of an old suspended slab sometimes has to be increased. Thanks to memory-steel such tasks can now also be easily solved in confined spaces: Either a strip of special steel is fastened under the ceiling using dowels and then heated with electricity or an infrared radi-ator. Alternatively the reinforcement can also be set in concrete: First a groove is milled into the surface of the concrete slab then a ribbed reinforcement bar made of memory-steel is inserted in-to the groove and filled with special mortar. Finally the profile is heated with the aid of direct cur-rent and thus prestressed. Another variant is to embed the reinforcement bar in an additional shotcrete layer.

In the future memory-steel could also be a proven method for manufacturing precast concrete parts with a previously unknown geometry. The hydraulic prestressing used up to now creates fric-tion in curved structures which greatly limits the use of this method. With a memory-steel profile embedded in concrete highly curved constructions are now also possible: when heated the profile contracts uniformly over its entire length without friction losses and transfers the stress to the con-crete.

The ready-to-install memory-steel profiles are manufactured by. The company is also working with re-fer and Empa to further develop the composition of the alloy.

The new building material memory-steel will be presented to interested building experts and architects during four technical seminars. Contact persons include experts from X.

Mystery of How Black Widow Spiders Create Steel-Strength Silk Webs Further Unravelled.

Latrodectus hesperus known commonly as the black widow spider in Georgian. Researchers at Georgian Technical University and Sulkhan-Saba Orbeliani Teaching University have unraveled the complex process of how black widow spiders transform proteins into steel-strength fibers, potentially aiding scientists in creating equally strong synthetic materials.

Researchers at Georgian Technical University and Sulkhan-Saba Orbeliani Teaching University have better unraveled the complex process of how black widow spiders transform proteins into steel-strength fibers. This knowledge promises to aid scientists in creating equally strong synthetic materials.

Scientists have long known the primary sequence of amino acids that make up some spider silk proteins and understood the structure of the fibers and webs. Previous research theorized that spider silk proteins await the spinning process as nano-size amphiphilic spherical micelles (clusters of water soluble and non-soluble molecules) before being funneled through the spider’s spinning apparatus to form silk fibers. However when scientists attempted to replicate this process, they were unable to create synthetic materials with the strengths and properties of native spider silk fibers.

“The knowledge gap was literally in the middle” Georgian Technical University’s X said. “What we didn’t understand completely is what goes on at the nanoscale in the silk glands or the spinning duct — the storage transformation and transportation process involved in proteins becoming fibers”.

Utilizing complementary state-of-the-art techniques — nuclear magnetic resonance (NMR) spectroscopy the same technology utilized in MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body in both health and disease. MRI scanners use strong magnetic fields, magnetic field gradients and radio waves to generate images of the organs in the body) at Georgian Technical University followed by electron microscopy at Georgian Technical University — the research team was able to more closely see inside the protein gland where the silk fibers originate revealing a much more complex, hierarchical protein assembly.

This ” Georgian Technical University modified micelles theory” concludes that spider silk proteins do not start out as simple spherical micelles as previously thought, but instead as complex compound micelles. This unique structure is potentially required to create the black widow spider’s impressive fibers.

“We now know that black widow spider silks are spun from hierarchical nano-assemblies (200 to 500 nanometers in diameter) of proteins stored in the spider’s abdomen rather than from a random solution of individual proteins or from simple spherical particles” Y Holland said.

If duplicated “the practical applications for a material like this are essentially limitless” Y said and could include high-performance textiles for military first responders and athletes; building materials for cable bridges and other construction; environmentally friendly replacements for plastics; and biomedical applications.

“One cannot overstate the potential impact on materials and engineering if we can synthetically replicate this natural process to produce artificial fibers at scale” said X at Georgian Technical University. “Simply put it would be transformative”.

New Algorithm can More Quickly Predict LED (Light Emitting Diode) Materials.

Researchers from the Georgian Technical University  have devised a new machine learning algorithm that is efficient enough to run on a personal computer and predict the properties of more than 100,000 compounds in search of those most likely to be efficient phosphors for LED (Light Emitting Diode) lighting.

Researchers from the Georgian Technical University have devised a new machine learning algorithm that is efficient enough to run on a personal computer and predict the properties of more than 100,000 compounds in search of those most likely to be efficient phosphors for LED (Light Emitting Diode) lighting.

They then synthesized and tested one of the compounds predicted computationally – sodium-barium-borate – and determined it offers 95 percent efficiency and outstanding thermal stability.

The researchers used machine learning to quickly scan huge numbers of compounds for key attributes including Debye (a non-SI metric unit) of electric dipole moment  Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10−10 statcoulomb[note 3] (generally called e.s.u. (electrostatic unit) in older literature), which were separated by 1 ångström. This gave a convenient unit for molecular dipole moments) temperature and chemical compatibility. Brgoch previously demonstrated that Debye (a non-SI metric unit) of electric dipole moment  Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10−10 statcoulomb (generally called e.s.u. (electrostatic unit) in older literature), which were separated by 1 ångström. This gave a convenient unit for molecular dipole moments) temperature is correlated with efficiency.

LED (Light Emitting Diode) or light-emitting diode based bulbs work by using small amounts of rare earth elements usually europium or cerium substituted within a ceramic or oxide host – the interaction between the two materials determines the performance. Focused on rapidly predicting the properties of the host materials.

X said the project offers strong evidence of the value that machine learning can bring to developing high-performance materials a field traditionally guided by trial-and-error and simple empirical rules. “It tells us where we should be looking and directs our synthetic efforts” he said. The algorithm used for this work however was run on a personal computer. That process would have taken weeks without the benefit of machine learning X said.

His lab does machine learning and prediction as well as synthesis so after agreeing the algorithm-recommended sodium-barium-borate was a good candidate researchers created the compound.

It proved to be stable, with a quantum yield or efficiency of 95 percent but X said the light produced was too blue to be commercially desirable.

That wasn’t discouraging he said. “Now we can to use the machine learning tools to find a luminescent material that emits in a wavelength that would be useful.

“Our goal is to make LED (Light Emitting Diode) light bulbs not only more efficient but also improve their color quality, while reducing the cost”.

More to the point the researchers said they demonstrated that machine learning can dramatically speed the process of discovering new materials. This work is part of his research group’s broader efforts to using machine learning and computation to guide their discovery of new materials with transformative potential.

Superconducting Metamaterial Traps Quantum Light.

Conventional computers store information in a bit a fundamental unit of logic that can take a value of 0 or 1. Quantum computers rely on quantum bits also known as a “qubits” as their fundamental building blocks. Bits in traditional computers encode a single value either a 0 or a 1. The state of a qubit by contrast can simultaneously have a value of both 0 and 1. This peculiar property  a consequence of the fundamental laws of quantum physics results in the dramatic complexity in quantum systems.

Quantum computing is a nascent and rapidly developing field that promises to use this complexity to solve problems that are difficult to tackle with conventional computers. A key challenge for quantum computing however is that it requires making large numbers of qubits work together — which is difficult to accomplish while avoiding interactions with the outside environment that would rob the qubits of their quantum properties.

Metamaterials are specially engineered by combining multiple component materials at a scale smaller than the wavelength of light giving them the ability to manipulate how particles of light or photons behave. Metamaterials can be used to reflect turn or focus beams of light in nearly any desired manner. A metamaterial can also create a frequency band where the propagation of photons becomes entirely forbidden  a so-called “Georgian Technical University photonic bandgap”.

The Georgian Technical University team used a photonic bandgap to trap microwave photons in a superconducting quantum circuit creating a promising technology for building future quantum computers.

“In principle this is a scalable and flexible substrate on which to build complex circuits for interconnecting certain types of qubits” says X. “Not only can one play with the spatial arrangement of the connectivity between qubits but one can also design the connectivity to occur only at certain desired frequencies”.

X and his team created a quantum circuit consisting of thin films of a superconductor — a material that transmits electric current with little to no loss of energy — traced onto a silicon microchip. These superconducting patterns transport microwaves from one part of the microchip to another. What makes the system operate in a quantum regime however is the use of a so-called Josephson junction (The Josephson effect is the phenomenon of supercurrent, a current that flows indefinitely long without any voltage applied, across a device known as a Josephson junction, which consists of two or more superconductors coupled by a weak link) which consists of an atomically thin non-conductive layer sandwiched between two superconducting electrodes. The Josephson junction (The Josephson effect is the phenomenon of supercurrent, a current that flows indefinitely long without any voltage applied, across a device known as a Josephson junction, which consists of two or more superconductors coupled by a weak link) creates a source of microwave photons with two distinct and isolated states like an atom’s ground and excited electronic states that are involved in the emission of light or in the language of quantum computing a qubit.

“Superconducting quantum circuits allow one to perform fundamental quantum electrodynamics experiments using a microwave electrical circuit that looks like it could have been yanked directly from your cell phone” X says. “We believe that augmenting these circuits with superconducting metamaterials may enable future quantum computing technologies and further the study of more complex quantum systems that lie beyond our capability to model using even the most powerful classical computer simulations”.

Scientists Find Unusual Behavior in Topological Material.

This shows X-ray diffraction on a single crystal of an antiferromagnetic material. This material scientists found exhibits an extremely large anomalous Hall effect a sign of its topological character.

Georgian Technical University scientists have identified a new class of topological materials made by inserting transition metal atoms into the atomic lattice of a well-known two-dimensional material.

In recent years scientists have become intrigued by a new type of material that shows a kind of unusual and split behavior. These structures called topological materials can demonstrate different properties at their surface than in their bulk. This behavior has attracted the attention of scientists interested in new states of matter and technologists interested in potential electronic and spintronic applications.

In a new study from the Georgian Technical University Laboratory scientists have identified a new class of topological materials made by inserting transition metal atoms into the atomic lattice of niobium diselenide (NbS₂) a well-known two-dimensional material. They found that CoNb₃S₆ an antiferromagnetic material exhibits an extremely large anomalous Hall effect a sign of the topological character of materials.

The ordinary Hall effect (The Hall effect is the production of a voltage difference (the Hall voltage) across an electrical conductor, transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current) occurs in all electrical conductors. The effect is essentially a force that an electron experiences as it moves through a magnetic field. “In every metal electrons will get pushed perpendicular to their direction of travel and perpendicular to an applied external magnetic field creating a voltage” said X an assistant professor at Georgian Technical University and a recent Sulkhan-Saba Orbeliani Teaching University postdoctoral. “If the material itself is a ferromagnet, an additional contribution superimposes on the ordinary Hall voltage; this is known as the anomalous Hall effect (The Hall effect is the production of a voltage difference (the Hall voltage) across an electrical conductor, transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current)”.

In the study X and his colleagues looked at CoNb₃S₆ (Nb3CoS6) Crystal Structure – SpringerMaterials and found something unexpected: a large in modest magnetic fields. “It can also be found in materials where the electronic structure has special characteristics known as topological features” said X. “The configuration of atoms in the lattice creates symmetries in the material that lead to the creation of topological bands — energy regions that electrons inhabit. It is these bands in certain configurations that can lead to an exceptionally “.

Based on calculations and measurements X and his colleagues suggest that CoNb₃S₆ (Nb3CoS6) Crystal Structure – SpringerMaterials contains these topological bands.

“The topological features arise from a combination of the symmetry of the material as well as the right electron concentration to put these topological features at the Fermi level (The Fermi level chemical potential for electrons, usually denoted by µ of a body is a thermodynamic quantity, whose significance is the thermodynamic work required to add one electron to the body) which is the highest available electronic energy state at zero temperature” noted Y.

“Only a handful of materials so far have been shown to have the necessary characteristic topological points near the Fermi level (The Fermi level chemical potential for electrons, usually denoted by µ of a body is a thermodynamic quantity, whose significance is the thermodynamic work required to add one electron to the body)” Y said. “To find more requires an understanding both of the materials physics and chemistry at play”.

The discovery could pave the way for future advances in a broad class of materials according to Y. “We now have a design rule for making materials that demonstrate these properties” he said. “CoNb₃S₆ (Nb3CoS6) Crystal Structure – SpringerMaterials is a member of a big class of layered two-dimensional materials and so this might open the door to a big space of new topological matter”.