Nanowerk November 1, 2022 Recent years witnessed a rebirth of the field of CDW materials and devices, partially driven by an interest in layered quasi-2D van der Waals materials where CDW phases can manifest themselves at room temperature. Despite numerous attempts, the electrical gating of the CDW phase, which is needed for many practical applications, remained elusive. An international team of researchers (USA – UC Riverside, University of Georgia, Poland) has demonstrated the electrical gating of the charge-density-wave phases and current in h-BN-capped three-terminal 1T-TaS2 heterostructure devices. The evolution of the hysteresis and the presence of abrupt spikes in the […]
Tag Archives: Materials science
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 […]
Penguin feathers may be secret to effective anti-icing technology
Phys.org October 24, 2022 The body feathers of perpetually ice-free penguins are very good natural examples of anti-icing surfaces, which use two different mitigation strategies for the two disparate problems – water adhesion and ice adhesion. Researchers in Canada constructed the form of the feather’s wire-like structure and decorated it with superimposed nanogrooves by laser micromachining fine woven wire cloths. Post-processing techniques also allowed them to isolate the role of surface chemistry by creating both hydrophilic and hydrophobic versions of the synthetic anti-icing surfaces. Their results showed that water-shedding and ice-shedding characteristics are indeed derived from different physical functions of […]
Researchers aim to solve the rare earths crisis
Phys.org October 18, 2022 Researchers have been searching for new magnetic materials that can act as substitutes for the critically scarce components. Researchers at Northeastern University have patented a process to accelerate the creation of a rare earth magnet alternative using tetrataenite, whose magnetic properties make it a leading candidate to replace magnets made of the scarce material. To make the new magnet they altered the atomic structures of its iron and nickel components by arranging them into a crystal structure that resembles tetrataenite. Industrial permanent magnets are used to transfer energy from mechanical to electrical sources. The list of […]
Researchers develop novel robust superhydrophobic coating
Phys.org October 18, 2022 Fragile hierarchical structures, fluorine-containing chemicals usage, and strict requirements for substrate scopes in biomimetic superhydrophobic coating remain thorny challenges. Researchers in China constructed a mechanical robust superhydrophobic ZnO@STA@PDMS coating with fluorine-free reagents through wide-applicable and substrate-independent spray-coating method. Different analyses and contact angle meter were used to assess the surface micro-nano structures, chemical compositions, thermal stability, and wettability variations. The corrosion resistance of the coating was reduced by two orders of magnitude after being spray-coated with superhydrophobic ZnO@STA@PDMS indicating excellent corrosion resistance in marine submerged zone. In simulated marine atmospheric conditions with high relative humidity, the […]
Scientists Transformed Pure Water Into a Metal, And There’s Footage
Science Alert October 20, 2022 By bringing pure water into contact with an alloy of sodium and potassium researchers in Czech Republic converted pure water metallic. They extruded a small blob of sodium-potassium alloy, which is liquid at room temperature, from a nozzle and added a thin film of pure water using vapor deposition. Upon contact, the electrons and metal cations flowed into the water from the alloy. Not only did this give the water a golden shine, but it also turned the water conductive. They confirmed this using optical reflection spectroscopy and synchrotron X-ray photoelectron spectroscopy. Their study not […]
‘Smart plastic’ material is step forward toward soft, flexible robotics and electronics
Science Daily October 13, 2022 An organized combination of stiff and elastic domains within a single material can synergistically tailor bulk mechanical properties. Researchers at UT Austin have developed a rapid, facile, and environmentally benign method to pattern strong and stiff semicrystalline phases within soft and elastic matrices using stereo-controlled ring-opening metathesis polymerization of an industrial monomer, cis-cyclooctene. Dual polymerization catalysis dictates polyolefin backbone chemistry, which enabled patterning of compositionally uniform materials with seamless stiff and elastic interfaces. Visible light–induced activation of a metathesis catalyst resulted in the formation of semicrystalline trans polyoctenamer rubber, outcompeting the formation of cis polyoctenamer […]