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Category: materials – Page 122

The spontaneous emergence of 1D superconducting stripes at a 2D interface in an oxide heterostructure

“Our research is inspired by the idea that unconventional superconductivity usually emerges in proximity to magnetism,” Xiang said. “In particular, for copper-based and iron-based , many of the proposed superconducting pairing mechanisms are closely connected to magnetism; moreover, the interplay between magnetism and superconductivity may give birth to more peculiar phases of matter, including the pair-density-wave (PDW) order with a spatially oscillating superconducting order parameter and finite-momentum pairing which has been an intense focus of research recently.”

The EuO/KTO heterostructure examined by Xiang and his colleagues exhibits a strong ferromagnetic proximity effect elicited by the EuO overlayer. This effect makes it an ideal platform to study unconventional superconductivity.

“The first report on the superconductivity at the EuO/KTO interface was published in 2021, focusing on the KTO (111) interface,” Xiang said. “We have since worked on the EuO/KTO (110) interface (considering its improved interface quality), at which we revealed the emergence of two-dimensional superconductivity in a previous paper.”

Researchers publish first-of-its-kind database for uranium minerals

Nuclear nonproliferation scientists at the Department of Energy’s Oak Ridge National Laboratory have published the Compendium of Uranium Raman and Infrared Experimental Spectra, or CURIES, a public database and analysis of structure-spectral relationships for uranium minerals. This first-of-its-kind dataset and corresponding analysis fill a key gap in the existing body of knowledge for mineralogists and actinide scientists.

Laser based vibrational spectroscopy methods such as Raman and IR are frequently employed by nonproliferation materials scientists because they are rapid, nominally non-destructive, and can give direct insight to what a material contains. Where spectral assignments may be difficult, the CURIES database uses structural information, subject matter expertise and statistical analysis to determine key features of Raman spectra based on their structural origins.

“When I was in grad school studying uranium mineralogy, there was no single repository to look up a feature of a sample and compare it for identification,” said ORNL’s Tyler Spano, lead author on the CURIES article in American Minerologist. “What we did was bring together data from many different sources including structural information and spectroscopy to understand spectral features and similarities as they relate to chemical, structural and other properties.” The ORNL team hopes that CURIES will support researchers who are looking for new relationships among various types of uranium materials and foster development of rapid characterization and analysis of spectra collected on new materials.

2D magnets could pave the way for green computing

A team of MIT researchers has addressed significant barriers to the practical application of 2D magnetic materials. This innovation will enable the development of the next generation of energy-efficient computers.

The team achieved a notable breakthrough by developing a “van der Waals atomically layered heterostructure” device. The device connects two 2D materials: tungsten ditelluride and iron gallium telluride, a 2D van der Waals magnet.

UE5-Made 3D Spruce Forest Scene With Next-Level Realism

MAWI United, a studio specializing in creating lifelike 3D environments, has once again pushed photorealism to the next level by presenting Dead Spruce Forest Tree Biome, a new procedural environment asset pack that lets you create AAA-quality forests in Unreal Engine 5.

Featuring over 200 photogrammetry-made plant, debris, and tree assets, as well as full Nanite support, the pack has everything you need to build next-level environments for your games and projects. As usual, MAWI’s latest creation comes with tools for procedural forest generation and interactive foliage and an advanced ground material with five different surface types (forest, meadow, wetland, stones, dirt) that automatically generates all the small ground cover and foliage.

Polar plastic: 97% of sampled Antarctic seabirds found to have ingested microplastics

Anthropogenic plastic pollution is often experienced through evocative images of marine animals caught in floating debris, yet its reach is far more expansive. The polar regions of the Arctic and Antarctica are increasingly experiencing the impacts of plastic reaching floating ice and land, not solely as larger macroplastics (>5 cm), but as microplastics (0.1 µm—5 mm) and nanoplastics (<0.1 µm) that may be carried vast distances from their source or be ingested in more populated areas during seasonal migration.

Grimshaw and UEL develop sugarcane-waste construction blocks

Using sugarcane waste as bricks for construction.

Architecture studio Grimshaw and the University of East London have collaborated to create Sugarcrete, a biomaterial construction block with an interlocking shape made from the sugarcane by-product bagasse.

Sugarcrete was developed to be a low-cost and low-carbon reusable construction-material alternative to brick and concrete.

The concept, design and fabrication of the material were led by staff and fellows of the University of East London (UEL), including senior architecture lecturer Armor Gutierrez Rivas, Sustainability Research Institute co-director Alan Chandler and research fellow Bamdad Ayati.

Intelligent Liquid” Created by Harvard Scientists Represents Strange “New Class of Fluid

Harvard researchers say they have developed a programmable metafluid they are calling an ‘intelligent liquid’ that contains tunable springiness, adjustable optical properties, variable viscosity, and even the seemingly magical ability to shift between a Newtonian and non-Newtonian fluid.

The team’s exact formula is still a secret as they explore potential commercial applications. However, the researchers believe their intelligent liquid could be used in anything from programmable robots to intelligent shock absorbers or even optical devices that can shift between transparent and opaque states.

“We are just scratching the surface of what is possible with this new class of fluid,” said Adel Djellouli, a Research Associate in Materials Science and Mechanical Engineering at Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS) and the first author of the paper. “With this one platform, you could do so many different things in so many different fields.”

Shape Matters in Self-Assembly

Many biological structures form through the self-assembly of molecular building blocks. A new theoretical study explores how the shape of these building blocks can affect the formation rate [1]. The simplified model shows that hexagonal blocks can form large structures much faster than triangular or square blocks. The results could help biologists explain cellular behavior, while also giving engineers inspiration for more efficient self-assembly designs.

Certain viruses and cellular structures are made from self-assembling pieces that can be characterized by geometrical shapes. For example, some types of bacteria host carboxysomes, which are icosahedral (20-face) compartments built up from self-assembling hexagonal and pentagonal subunits.

To investigate the role of shape, Florian Gartner and Erwin Frey from Ludwig Maximilian University of Munich simulated self-assembly of two-dimensional structures with three types of building blocks: triangles, squares, and hexagons. The model assumed that the blocks bind along their edges, but these interactions are reversible, meaning that the resulting structures can fall apart before growing very large. Gartner and Frey found that certain shapes were better than others at assembling into larger structures, as they tended to form intermediate structures with more bonds around each block. In particular, hexagonal blocks were the most efficient building material, forming 1000-piece structures at a rate that was 10,000 times faster than triangular blocks.

A Counterintuitive Set of Tunneling Effects Observed at Last

Graphene is the setting for the first demonstration of relativistic electrons’ paradoxical ability to whiz through a barrier, provided the barrier is high enough.

If an electron in a material has a speed that is independent of its energy and if it encounters a barrier head on, it can tunnel straight through. Derived by theorist Oskar Klein in 1929, this counterintuitive finding remained little tested in the lab because it is hard to make electrons approach a barrier head on and to stop them scattering off the edges of the sample. Now Mirza Elahi of the University of Virginia and his collaborators have observed evidence of Klein tunneling in monolayer graphene. What’s more, they also observed the opposite effect, anti-Klein tunneling, in bilayer graphene. In anti-Klein tunneling, head-on electrons do not tunnel at all, while others approaching the barrier at an intermediate angle do [1].

Graphene’s hexagonal lattice can be thought of as two identical interpenetrating triangular sublattices. One consequence of that view is that graphene’s charge carriers—electrons that hop between the two sublattices—behave as if massless and relativistic at low energies. Another consequence is that the two sublattices bestow on the electrons a chiral property, pseudospin, that resembles spin, which controls the nature of the transmission across the barrier.

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