Team creates protein-based material that can stop supersonic impacts

Phys.org  December 13, 2022 Extreme energy dissipating materials are essential for a range of applications, in the military, law enforcement, aerospace industry to name a few. Researchers in the UK have created and patented a new shock-absorbing material that could revolutionize both the defense and planetary science sectors. They incorporated a recombinant form of the mechanosensitive protein talin into a monomeric unit and crosslinked, resulting in the production of a talin shock absorbing material (TSAM). When subjected to 1.5 km/s supersonic shots, TSAMs were shown not only to absorb the impact, but to capture/preserve the projectile. According to the researchers […]

Growing a tiny metallic snowflake

Nanowerk  December 10, 2022 Nanoscale structures can aid electronic manufacturing, make materials stronger yet lighter, or aid environmental clean-ups by binding to toxins. An international team of researchers (Australia, New Zealand) developed an extraction method achieved by applying a voltage to the liquid metal solution while vacuum filtrating. The resulting crystals can have intricate morphologies like snowflakes. They used the low-melting-temperature Ga as a “metallic solvent” to synthesize a range of flake-like Zn crystals. They extracted the metallic crystals from the liquid metal solvent by reducing its surface tension using a combination of electrocapillary modulation and vacuum filtration. The crystals […]

International research team creates previously unknown nitrogen compounds

Phys.org  December 9, 2022 Non-metal nitrides contain structural units whose existence could not be empirically proven before. An international team of researchers (Germany, Sweden, USA – University of Chicago, France) synthesized previously unknown modification of the phosphorus nitride P₃N₅ at a pressure of 72 gigapascals. At 134 gigapascals, the phosphorus nitride PN₂ formed in the diamond anvil cell. They discovered that a key reason for this extreme strength was that the crystal structures of δ-P₃N₅ and PN₂ consist of a dense network of PN₆ octahedra with a phosphorus atom surrounded by six nitrogen atoms. The polymorph δ-P₃N₅ transformed into another […]

Using machine learning to infer rules for designing complex mechanical metamaterials

Phys.org  November 23, 2022 Combinatorial problems arising in puzzles, origami, and (meta) material design have rare sets of solutions, which define complex and sharply delineated boundaries in configuration space. The boundaries are difficult to capture with conventional statistical and numerical methods. Researchers in the Netherlands have shown that convolutional neural networks can learn to recognize these boundaries for combinatorial mechanical metamaterials, down to the finest detail, despite using heavily undersampled training sets, and can successfully generalize. According to the researchers even if machine learning is typically a “black box” approach, it can still be very valuable for exploring the design […]

Scientists synthesize an analog of the Earth’s most complex mineral in a laboratory

Phys.org  November 21, 2022 Through the combination of low-temperature hydrothermal synthesis and room-temperature evaporation an international team of researchers (Russia, Czech Republic, USA – University of Notre Dame) has synthesized a mineral similar in composition and crystal structure to the Earth’s most complex mineral, ewingite. The crystal structures of both natural and synthetic compounds were based on supertetrahedral uranyl-carbonate nanoclusters that are arranged according to the cubic body-centered lattice principle. The structure and composition of the uranyl carbonate nanocluster were refined using the data on synthetic material. Although the stability of natural ewingite is higher (according to visual observation and […]

Team creates crystals that generate electricity from heat

Phys.org  November 6, 2022 An international team of researchers (France, Japan, Germany) synthesized a series of self-doped compounds Cu2+xMn1−xGeS4 through Cu for Mn substitution. Using a combination of powder X-ray diffraction, high resolution transmission electron microscopy and precession-assisted electron diffraction tomography, they showed that the materials were composed of interconnected enargite- and stannite-type structures, via the formation of nanodomains with a high density of coherent interfaces. By combining experiments with ab initio electron and phonon calculations, they discussed the structure–thermoelectric properties relationships and clarified the interesting crystal chemistry in this system. They demonstrated that excess Cu+ substituted for Mn2+ dopes […]

In nanotube science, is boron nitride the new carbon?

Nanowerk   October 31, 2022 Boron nitride nanotubes (BNNTs) possess a broad range of applications because of several engineering-relevant properties, including high specific strength and stiffness, thermal stability, and transparency to visible light. The morphology of the nanoscale fibers must be controlled to maximize such properties, which can be achieved by synthesizing long aligned arrays of crystalline hexagonal boron nitride (hBN) nanotubes. An international team of researchers (USA – MIT, Japan) synthesized high-quality millimeter length, vertically aligned (VA-) BNNTs using free-standing carbon nanotube (CNT) arrays as scaffolds. In addition to high optical transparency of the VA-BNNTs, they also demonstrated several micro- […]

Scientists discover material that can be made like a plastic but conducts like metal

Science Daily  October 26, 2022 An international team of researchers (USA – University of Chicago, Stony Brook University, Argonne National Laboratory, South Korea) discovered a way to create a material that can be made like a plastic but conducts electricity more like a metal when they strung nickel atoms like pearls into a string of molecular beads made of carbon and sulfur. The material easily and strongly conducted electricity when heated or chilled or exposed to air and humidity, or even dripped acid and base. But the most striking thing was that the molecular structure of the material was disordered. […]

New approach to ‘cosmic magnet’ manufacturing could reduce reliance on rare earths in low-carbon technologies

Science Daily  October 24, 2022 Tetrataenite, an iron-nickel alloy with a particular ordered atomic structure, is one of the most promising material to replace rare earth magnet. It forms over millions of years as a meteorite slowly cools, giving the iron and nickel atoms enough time to order themselves into a particular stacking sequence within the crystalline structure, ultimately resulting in a material with magnetic properties approaching those of rare-earth magnets. The 1960s technique for forming tetrataenite is not suitable for mass production. An international team of researchers (Italy, Austria, UK) found a possible alternative that doesn’t require millions of […]

The next wonder semiconductor

Science Daily  October 25, 2022 Cubic boron arsenide (BAs) is promising for microelectronics thermal management because of its high thermal conductivity. Recently, its potential as an optoelectronic material was explored. However, it remains challenging to measure its photocarrier transport properties because of small sizes of available high-quality crystals. A team of researchers in the US (UC Santa Barbara, University of Houston) used scanning ultrafast electron microscopy (SUEM) to directly visualize the diffusion of photocarriers in BAs single crystals. They observed ambipolar diffusion at low optical fluence with persistent hot carrier dynamics for above 200 ps, which could likely be attributed […]