2D materials

Researchers use trilayer graphene to achieve superconducting diode effect without external magnetic field

Researchers from Brown University, the University of New South Wales, Columbia University, University of Innsbruck, and the National Institute for Materials Science in Japan have carried out new experiments involving trilayer graphene, in which an external magnetic field is not required in order to achieve the 'superconducting diode effect' - a material that behaves like a superconductor in one direction of current flow and like a resistor in the other.

In contrast to a conventional diode, such a superconducting diode exhibits a completely vanishing resistance and thus no losses in the forward direction. This could form the basis for future lossless quantum electronics. Physicists have already succeeded in creating the diode effect, but with some fundamental limitations. "At that time, the effect was very weak and it was generated by an external magnetic field, which is very disadvantageous in potential technological applications," explains Mathias Scheurer from the Institute of Theoretical Physics at the University of Innsbruck. The new experiments confirmed a thesis previously theorized by Scheurer: Namely, that superconductivity and magnetism coexist in a system consisting of three graphene layers twisted against each other. The system thus virtually generates its own internal magnetic field, creating a diode effect.

Read the full story Posted: Aug 22,2022

Researchers detect unexpected quantum effects in natural double-layer graphene

An international research team that included scientists from the University of Göttingen, Ludwig-Maximilians-Universität München, National Institute for Materials Science in Tsukuba, Japan, and University of Texas at Dallas, has detected and interpreted novel quantum effects in high-precision studies of natural double-layer graphene.

This research provides new insights into the interaction of the charge carriers and the different phases, and contributes to the understanding of the processes involved.

Read the full story Posted: Aug 16,2022

Versarien launches graphene-based superparamagnetic material

Versarien has announced the launch of a new hybrid nanomaterial that has superparamagnetic properties, which can be used across a range of applications, like defense and healthcare. The new material combines graphene with both iron oxide and manganese oxide nanoparticles and its development was led by Versarien's 62% owned subsidiary, Gnanomat.

The superparamagnetic material combines graphene with both iron oxide and manganese oxide nanoparticles that provide the material with magnetic properties. In return, graphene provides electrical conductivity to these electrically insulating metal oxides. Magnetic nanocomposites can readily respond to external magnetic fields which allow them to be manipulated. Potential applications of the material include the treatment of wastewater whereby pollutants are adsorbed onto the graphene surface. The material could also lends be used in biomedical and biotechnology applications, or defense applications requiring the shielding of electromagnetic fields. Magnetic manipulation could allow the recovery and recycling of the graphene, something that could not be done with normal graphene compounds.

Read the full story Posted: Jun 27,2022

Researchers succeed in synthesizing graphyne

Researchers at the University of Colorado Boulder and Qingdao University of Science and Technology have managed to synthesize an illusive form of carbon called graphyne. Graphyne has long been of interest to scientists because of its similarities to graphene. However, despite decades of work and theorizing, only a few fragments have ever been created before now.

Graphyne created for first time image

"The whole audience, the whole field, is really excited that this long-standing problem, or this imaginary material, is finally getting realized," said Yiming Hu, lead author on the paper.

Read the full story Posted: May 22,2022

Japan launches a $8.5 million project to study 2.5D materials

Japan's Ministry of Education, Culture, Sports, Science and Technology has launched a collaborative project to develop 2.5D materials. The project, titled "Science of 2.5 Dimensional Materials: Paradigm Shift of Materials Science Toward Future Social Innovation" includes 40 researchers in Japan, led by Prof. Ago Hiroki at Kyushu University.

2.5D material chart, Kyushu University

2.5D materials are made by stacking different 2D materials artificially by using advanced transfer techniques. These new materials are not limited by lattice constant or composition, and it is possible to control the material layers, and their stacking angle. These new materials could unlock new breakthroughs in materials science.

Read the full story Posted: May 07,2022

Researchers succeed in synthesizing single layers of hexagonal boron nitride on graphene

A research team led by the University of Michigan has developed a reliable, scalable method for growing single layers of hexagonal boron nitride on graphene.

Graphene-hBN structures can power LEDs that generate deep-UV light, which is impossible in today's LEDs, said Zetian Mi, U-M professor of electrical engineering and computer science and a corresponding author of the study. Deep-UV LEDs could drive smaller size and greater efficiency in a variety of devices including lasers and air purifiers.

Read the full story Posted: Apr 24,2022

Researchers detect evidence of strong electron correlation in a trilayer graphene/hBN moiré superlattice

Researchers from MIT, Harvard University, University of California at Berkeley, Lawrence Berkeley National Laboratory, China's Shanghai Jiao Tong and Fudan Universities and Japan's National Institute for Materials Science have taken a significant step toward understanding electron correlations.

In their new study, the researchers revealed direct evidence of electron correlations in a two-dimensional material called ABC trilayer graphene. This material has previously been shown to switch from a metal to an insulator to a superconductor.

Read the full story Posted: Mar 22,2022

MIT researchers manage to create a 2D polymer material for the first time

Researchers from MIT created a new 2D material, called 2DPA-1, which is the world's first 2D polymer. Until now, it was actually believed to be impossible to induce polymers into a 2D sheet.

To create the material, the researchers used a novel polymerization process, that was used to generate a two-dimensional sheet called a polyaramide. For the monomer building blocks of the material, they use a compound called melamine, which contains a ring of carbon and nitrogen atoms. Under the right conditions, these monomers can grow in two dimensions, forming disks. These disks stack on top of each other, held together by hydrogen bonds between the layers, which make the structure very stable and strong.

Read the full story Posted: Feb 05,2022

Graphene enables the creation of new 2D materials

Researchers at the University of Vienna, in collaboration with the Universities of Tübingen, Antwerp and CY Cergy Paris and working with Danubia NanoTech, have developed a graphene-based method to produce 2D materials. They have already produced a new 2D material made of copper and iodine atoms sandwiched between two graphene sheets.

A single layer of cuprous iodide encapsulated in between two sheets of graphene imageA single layer of cuprous iodide encapsulated in between two sheets of graphene (gray atoms). Image from Phys.org, credit: Kimmo Mustonen, Christoph Hofer and Viera Skákalov

Following the 2D copper iodide, the researchers have already expanded the synthesis method to produce other new 2D materials. "The method seems to be truly universal, providing access to dozens of new 2D materials. These are truly exciting times," Kimmo Mustonen, the lead author of the study, said.

Read the full story Posted: Jan 21,2022