Science Daily April 5, 2022 Grid-level storage of seasonal excess can be an important asset to renewable electricity. As a proof-of-concept researchers at Pacific Northwest National Laboratory applied the freeze-thaw thermal cycling strategy to Al-Ni molten salt batteries and demonstrated effective capacity recovery over 90% after a period of 1–8 weeks. They explored three activation methods of the nickel cathode in a molten-salt battery: (1) heat treating the cathode granules under H2/N2, (2) incorporating a partially charged NiCl2/Ni cathode, and (3) doping the molten salt electrolyte with sulfur. Sulfur doping, a cost-efficient method suitable for large-scale applications, was not only […]
Making a ‘sandwich’ out of magnets and topological insulators, potential for lossless electronics
Nanowerk April 3, 2022 Inducing magnetic order in topological insulators via proximity to a magnetic material offers a promising pathway towards achieving quantum anomalous Hall (QAH) effect at higher temperatures for lossless transport applications. An international team of researchers (Australia, Singapore, USA – UC Berkeley) demonstrated the growth of a MnBi2Te4 / Bi2Te3 /MnBi2Te4 heterostructure via molecular beam epitaxy and probed the structure’s electronic structure using angle resolved photoelectron spectroscopy. They observed strong hexagonally warped massive Dirac fermions and a bandgap of 75 ± 15 meV. The 2D MnBi2Te4 ferromagnets induced magnetic order in the ultra-thin topological insulator Bi2Te3 via […]
Nanomaterials: Light dependent atom clusters for sensing applications
Phys.org April 1, 2022 An international team of researchers (Japan, France, Germany, Switzerland) has developed a new environment-sensing device based on the opto-ionic-electronic phenomena of an octahedral molybdenum metal (Mo6) cluster. When the Mo6 cluster is electrochemically deposited on a transparent electrode in an organic solvent containing a trace amount of water, the water permeates the deposited film. During the process, some ligand species that stabilize the frame structure of the Mo6 cluster are substituted with hydroxyl groups, and the negatively charged frame structure of the Mo6 cluster unit is stabilized by hydronium counterions. As a result, the transparent film […]
Nano particle trapped between mirrors works as a quantum sensor
Science Daily April 7, 2022 In an optical resonator light is reflected between mirrors, and it interacts with the levitated nanoparticle. Such interaction can give rise to dynamical instabilities which are often considered undesirable. An international team of researchers (Austria, Switzerland) has shown how they can be used as a resource. They have shown that by properly controlling these instabilities, the resulting unstable dynamics of a mechanical oscillator inside an optical cavity leads to mechanical squeezing. They applied this approach to a silica nanoparticle coupled to a microcavity via coherent scattering. The new protocol is robust in the presence of […]
NASA uses moonlight to improve satellite accuracy
Phys.org April 4, 2022 The Moon is extremely stable and not influenced by factors on Earth like climate to any large degree. It is a very good calibration reference. An international team of researchers in (US – NIST, USGS, Canada) developed NASA’s airborne Lunar Spectral Irradiance (air-LUSI) which is a telescope that accurately measures how much light is reflected off the lunar surface to assess the amount of energy Earth-observing satellites receive from moonlight. It will help to improve the accuracy and consistency of measurements among Earth-observing satellites. The results will compliment ground-based sites. Scientists can more easily compare data […]
New quantum dots for quantum networks
Phys.org April 7, 2022 Spin can be also used as the medium for quantum communication by transferring quantum information with light. But the process of transferring information to the spin of extremely small electrons is challenging and must be performed efficiently. An international team of researchers (Japan, Canada, Germany) has realized the world’s first GaAs gate-controlled quantum dot circuit on a (110)-oriented surface that promises to increase photon-electron spin conversion efficiency. This has the effect of encoding quantum information from incident photons into the electron spins. Because of the way the hole interacts with the GaAs crystal lattice, the g-factor, […]
New study solves mystery of how soft liquid droplets erode hard surfaces
Science Daily March 31, 2022 An international team of researchers (USA – University of Minnesota, Chile) has developed a method of high-speed stress microscopy, which measures the key dynamic properties of drop impact responsible for erosion, i.e., the shear stress and pressure distributions of impacting drops, with unprecedented spatiotemporal resolutions. Their experiments revealed the fast propagation of self-similar noncentral stress maxima underneath impacting drops and quantify the shear force on impacted substrates. They examined the deformation of elastic substrates under impact and uncovered impact-induced surface shock waves. The study opens the door for quantitative measurements of the impact stress of […]
Pollen paper that you can print on and ‘unprint’
Nanowerk April 5, 2022 Conventional paper is made of cellulose fibres found in wood, and the process involves energy-intensive steps that include logging, debarking, and chipping. Making pollen-based paper is similar to traditional soapmaking, which is much simpler and less energy-intensive. Researchers in Singapore used potassium hydroxide to remove the cellular components encapsulated in tough sunflower pollen grains and turned them into soft microgel particles. This step also removes allergens from the pollen. They used deionized water to remove unwanted particles from the microgel, before casting it into a 22 cm x 22 cm mould for air-drying, forming a piece […]
Quantum ‘shock absorbers’ allow perovskite to exhibit superfluorescence at room temperature
Phys.org March 31, 2022 While analyzing the structure and optical properties of a common lead-halide hybrid perovskite an international team of researchers (USA – North Caroline State University, France) noticed the formation of polarons in these materials. Their analysis showed that formation of large polarons creates a thermal vibrational noise filter mechanism that they called ‘Quantum Analog of Vibration Isolation,’ or QAVI, which is like a shock absorber protecting the dipoles. When they are protected by the shock absorbers, the dipoles can synchronize and exhibit superfluorescence. According to the researchers, QAVI is an intrinsic property that exists in certain materials, […]
Researchers develop glass-in-glass fabrication approach for making miniature IR optics
Phys.org April 7, 2022 Glass that transmits IR wavelengths is essential for many applications. However, infrared glasses are difficult to manufacture, fragile and degrade easily in the presence of moisture. Researchers in Switzerland have developed a new technique where they created an arbitrarily shaped 3D cavity inside a fused silica glass substrate using femtosecond laser-assisted chemical etching. They used a miniaturized version of pressure-assisted casting, in which a second material was melted and pressurized so that it could flow and solidify within the network of carved silica cavities. The second material can be a metal, glass, or any material with […]