EurekAlert May 23, 2019 Plumbene is a lead-based 2D honeycomb material that has the largest spin-orbit interaction, due to lead’s orbital electron structure and therefore the largest energy band gap, potentially making it a robust 2D topological insulator in which the Quantum Spin Hall Effect might occur even above room temperature. An international team of researchers (Japan, France) created plumbene by annealing an ultrathin lead (Pb) film on palladium Pd(111). The resulting surface material has the signature honeycomb structure of a 2D monolayer. Beneath the plumbene, a palladium-lead (Pd-Pb) alloy thin film forms with a bubble structure. Atomic‐scale STM images […]
Category Archives: Advanced materials
Promising material could lead to faster, cheaper computer memory
Science Daily May 2, 2019 Bismuth ferrite (BiFeO3) has the potential to store information much more efficiently than is currently possible. However, its magnetoelectric response is small. Researchers at the University of Arkansas simulated conditions that enhance the magnetoelectric response to the point that it could be used to more efficiently store information by using electricity, rather than magnetism. They found additional oscillations consisting of a mixing between acoustic phonons, optical phonons, and magnons, and reflect the existence of a new quasiparticle that can be coined an “electroacoustic magnon.” The finding could help tune the samples to the magnetostrictive-induced mechanical […]
Mimicking squid skin to improve thermoregulating blankets
Physics World May 2, 2019 Squid skin contains embedded chromatophore organs that are packed with pigment granules. These cells contract and expand thereby changing the wavelengths of light they absorb and reflect. Inspired by the squid skin a team of researchers in the US (UC Irvine, industry) designed a composite thermoregulatory material made up of a soft and stretchable infrared-transparent polymer matrix covered with an array of infrared-deflecting metal domains stably anchored within the matrix. In the relaxed state, the materials reflect nearly all incoming infrared radiation. When stretched, however, the anchored metal domains move apart and uncover parts of […]
‘A Swiss cheese-like material’ that can solve equations
University of Pennsylvania March 21, 2019 Researchers at the University of Pennsylvania have introduced a metamaterial platform capable of solving an arbitrary wave as the input function to an equation associated with a prescribed integral operator. The solution of such an equation is generated as a complex-valued output electromagnetic field. They demonstrated their technique at microwave frequencies through solving a generic integral equation and using a set of waveguides as the input and output to the designed metastructures. The research provides a route to develop chip-based analog optical computers and computing elements…read more. TECHNICAL ARTICLE
Supercrystal: A hidden phase of matter created by a burst of light
Science Daily March 18, 2019 A team of researchers in the US (Pennsylvania State University, Oak Ridge National Laboratory, Argonne National Laboratory, UC Berkeley, Lawrence Livermore National Laboratory) has shown that atomic-scale PbTiO3/SrTiO3 superlattices, counterpoising strain and polarization states in alternate layers, are converted by sub-picosecond optical pulses to a supercrystal phase. This phase persists indefinitely under ambient conditions, has not been created via equilibrium routes, and can be erased by heating. By adjusting only dielectric properties, the phase-field model describes this emergent phase as a photo-induced charge-stabilized supercrystal formed from a two-phase equilibrium state. The research has implications for […]
Materials could delay frost up to 300 times longer than existing anti-icing coatings
Nanowerk March 21, 2019 An international team of researchers (USA – University of Illinois, France) has demonstrated that the use of certain phase‐change materials, called phase‐switching liquids (PSLs), which are in liquid state under ambient conditions and have melting point higher than the freezing point of water can impede condensation–frosting lasting up to 300 and 15 times longer in bulk and surface infused state, respectively. The freezing delay is primarily a consequence of the release of trapped latent heat due to condensation, solidified PSL surface morphology and its miscibility in water. Regardless of surface chemistry, PSL‐infused textured surfaces exhibit low […]
NUS researchers create water-resistant electronic skin with self-healing abilities
Eurekalert March 18, 2019 An international team of researchers (China Singapore) has developed a material inspired by jellyfish. It is composed of a fluorocarbon elastomer and a fluorine-rich ionic liquid, has an ionic conductivity that can be tuned to as high as 10−3 S cm−1 and can withstand strains as high as 2,000%. Owing to ion–dipole interactions, it offers fast and repeatable electro-mechanical self-healing in wet, acidic and alkali environments. It can be printed into soft and pliable ionic circuit boards and touch, pressure and strain sensors. The material has applications in aquatic soft robots and water-resistant human–machine interfaces…read more. TECHNICAL ARTICLE
Nanocoating makes lightweight metal foams bone-hard and explosion-proof
Phys.org March 15, 2019 The metal foams currently available are suitably lightweight, but the production process is complicated and expensive, and the structures are still too weak and not resilient enough for many applications. Inspired by bone, researchers in Germany used aluminium or polymer foam as the initial lattice substrate to manufacture highly stable, porous metallic foams. They developed a proprietary procedure for coating the individual struts that make up the open-cell interior lattice. As a result, the exterior of the foam is stronger, more stable, light and the withstands extreme loads. They found polyurethane foams have a low density, […]
‘Meta-mirror’ reflects sound waves in any direction
Science Daily March 7, 2019 To break the law of reflection with sound waves, an international team of researchers (Finland, USA – Duke University) designed a meta-mirror out of plastic with precisely etched channels on the surface of the metamaterial. Between the meta-mirror’s shape and the depth of its channels, the interference pattern results in the sound wave reflecting in a desired direction without any of its energy being absorbed or scattered in an unwanted direction. In demonstration the device reflected a soundwave traveling directly toward it at 3,000 Hertz and perfectly reflects it at an angle of 70 degrees. […]
Organic electronics: Scientists develop a high-performance unipolar n-type thin-film transistor
Science Daily March 1, 2019 Researchers in Japan used a series of new poly(benzothiadiazole-naphthalenediimide) derivatives and fine-tuned the material’s backbone conformation introducing vinylene bridges capable of forming hydrogen bonds with neighboring fluorine and oxygen atoms. Overall, the resultant material had an improved molecular packaging order and greater strength, which contributed to the increased electron mobility. The material achieved an electron mobility of 7.16 cm2 V-1 s-1, representing more than a 40 percent increase over previous comparable results.The researchers will also aim to improve the air stability of n-channel transistors — a crucial issue for realizing practical applications that would include […]