Science Daily April 11, 2024 Studies of electric field-driven insulator-to-metal (IMT) in the prototypical vanadium dioxide (VO2) thin-film channel devices are largely focused on the electrical and elastic responses of the films, but the response of the corresponding Titanium dioxide (TiO2) substrate is often overlooked. An international team of researchers (USA – Pennsylvania State University, Cornell University, Argonne National Laboratory, Germany) found that in-operando spatiotemporal imaging of the coupled elastodynamics using X-ray diffraction microscopy of a VO2 film channel device on TiO2 substrate the film channel bulged during the IMT instead shrinking as expected. A micron thick proximal layer in […]
Tag Archives: Advanced materials
This 3D printer can figure out how to print with an unknown material
Science Daily April 8, 2024 An international team of researchers (USA – MIT, National Institute of Standards and Technology, Greece) described a new method for the automatic generation of process parameters for fused filament fabrication (FFF) across varying machines and materials. They used an instrumented extruder to fit a function that maps nozzle pressures across varying flow rates and temperatures for a given machine and material configuration and developed a method to extract real parameters for flow rate and temperature using relative pressures and temperature offsets. Using their method they found process parameters, using one set of input parameters, across […]
Magnetic levitation: New material offers potential for unlocking gravity-free technology
Phys.org April 8, 2024 An international team of researchers (Japan, Taiwan, Mexico, Australia) demonstrated the passive, diamagnetic levitation of a centimeter-sized massive oscillator, which was fabricated ensuring that the material, though highly diamagnetic, was an electrical insulator. By chemically coating a powder of microscopic graphite beads with silica and embedding the coated powder in high-vacuum compatible wax, they formed a centimeter-sized thin square plate which magnetically levitated over a checkerboard magnet array. The insulating coating reduced eddy damping by almost an order of magnitude compared to uncoated graphite with the same particle size. The plates exhibited a different equilibrium orientation […]
Supercomputer simulations of super-diamond suggest a path to its creation
Phys.org March 18, 2024 Despite several experimental attempts, synthesis, and recovery of the theoretically predicted post-diamond BC8 phase remains elusive. Through quantum-accurate multimillion atom molecular dynamics (MD) simulations, an international team of researchers (USA – University of South Florida, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Sweden) uncovered the extreme metastability of diamond at very high pressures, significantly exceeding its range of thermodynamic stability. They predicted the post-diamond BC8 phase to be experimentally accessible only within a narrow high pressure–temperature region of the carbon phase diagram. The diamond to BC8 transformation proceeded through premelting followed by BC8 nucleation and […]
Materials research explores design rules and synthesis of quantum memory candidates
Phys.org March 11, 2024 Stoichiometric Eu3+ compounds have recently shown promise for building dense, optically addressable quantum memory as the cations’ long nuclear spin coherence times and shielded 4f electron optical transitions provide reliable memory platforms but finding rare linewidth behavior within a wide range of potential chemical spaces remains difficult. Researchers at the University of Illinois, Urbana─Champaign, have found density functional theory (DFT) procedures that reliably reproduce known phase diagrams and correctly predict two experimentally realized quantum memory candidates. They synthesized the double perovskite halide Cs2NaEuF6 which is an air-stable compound with a calculated band gap of 5.0 eV […]
Research team develops a more durable coating against ice
Phys.org February 27, 2024 An international team of researchers (Austria, Italy) deposited gradient polymers in one step via initiated chemical vapor deposition as an effective coating to mitigate ice accretion and reduce ice adhesion. The gradient structures easily overcame adhesion, stability, and durability issues of traditional fluorinated coatings. The coatings showed promising ice phobic performance by reducing ice adhesion, depressing the freezing point, delaying drop freezing, and inhibiting ice nucleation and frost propagation. They confirmed that lipophobicity correlated with surface energy discontinuities at the surface plane resulting from the random orientation of the fluorinated groups of PFDA. It could be […]
Researchers create new compound to build space-age antennas
Science Daily February 29, 2024 Additive manufacturing with high-performance polymers can realize lightweight and complex geometries that can also be manufactured on board. However, polymers are electromagnetically inefficient for applications requiring electrical conductivity, such as guiding microwave signals. An international team of researchers (Canada, USA – Drexel University) developed MXene coated high-efficiency, lightweight additively manufactured microwave components with waveguiding functionality from 8 to 33 GHz, covering low earth orbit (LEO) frequencies, with a power-handling capability up to 10 dB and a transmission coefficient of 93 %. After a single dip-coating cycle, the polymer waveguide performed only 2 % below an […]
Novel nanocrystal harnesses full solar spectrum for hydrogen production
Nanowerk February 27, 2024 Near infrared energy remains untapped toward the maneuvering of entire solar spectrum harvesting for fulfilling the nuts and bolts of solar hydrogen production. An international team of researchers (Taiwan, Japan)used Au@Cu7S4 yolk@shell nanocrystals as dual-plasmonic photocatalysts to achieve remarkable hydrogen production under visible and near infrared illumination. Data revealed the prevalence of long-lived charge separation states for Au@Cu7S4 under both visible and near infrared excitation. Combined with the advantageous features of yolk@shell nanostructures, Au@Cu7S4 achieved a peak quantum yield of 9.4%. The design of a sustainable visible- and near infrared-responsive photocatalytic system is expected to inspire […]
Physicists detect elusive ‘Bragg glass’ phase with machine learning tool
Phys.org February 9, 2024 Detecting the Bragg glass phase has been challenging despite its sharp theoretical definition in terms of diverging correlation lengths. A team of researchers in the US (Cornell University, Stanford University, National Accelerator Laboratory, Argonne National Laboratory provided bulk probe evidence supporting a Bragg glass phase in the systematically disordered charge-density-wave material of PdxErTe3. They established a diverging correlation length in samples with moderate intercalation over a wide temperature range. According to the researchers their work advances our understanding of the complex interplay between disorder and fluctuation and the use of their analysis technique to target fluctuations […]
Strange New Kind of Magnetism Found Lurking In Material Just Six Atoms Thick
Science Alert February 4, 2024 The existence of alternate mechanisms for magnetism that could naturally facilitate electrical control has been discussed theoretically but an experimental demonstration has not been done. An international team of researchers (Switzerland, Spain, US -University of Tennessee, Japan) investigated MoSe2/WS2 van der Waals heterostructures in the vicinity of Mott insulator states of electrons forming a frustrated triangular lattice and observed direct evidence of magnetic correlations originating from a kinetic mechanism. By directly measuring electronic magnetization they found that when the Mott state was electron-doped, the system exhibited ferromagnetic correlations in agreement with the Nagaoka mechanism… read […]