Nanowerk July 10, 2023 Phase change memory could potentially revolutionize data storage because of its high storage density, and faster read and write capabilities. But still, the complex switching mechanism and intricate fabrication methods associated with these materials have posed challenges for mass production. Unlike conventional amorphous-crystalline PCMs, NbTe4 demonstrates both a low melting point and a high crystallization temperature. This unique combination offers reduced reset energies and improved thermal stability at the amorphous phase. Researchers in Japan fabricated NbTe4 and evaluated its switching performance. It exhibited a significant reduction in operation energy compared to conventional phase-change memory compounds. The […]
Tag Archives: Advanced material
Physicists probe ‘astonishing’ morphing properties of honeycomb-like material
Science Daily October 12, 2022 A team of researchers in the US (University of Colorado, Georgia Institute of Technology, Oak Ridge National Laboratory, University of Kentucky) synthesized a quantum material which has the chemical formula Mn3Si2Te6 and has “honeycomb” structure because its manganese and tellurium atoms form a network of interlocking octahedra that look like the cells in a beehive. Under most circumstances, it behaved a lot like an insulator. When it was exposed to magnetic fields in a certain way, it suddenly morphed from rubber into metal in behavior. The team explained this behavior as an exotic quantum state […]
Unique quantum material could enable ultra-powerful, compact computers
Phys.org May 20, 2022 A long-standing challenge has been to realize materials that integrate and connect tunable electrical transport and tunable spin configurations. Two-dimensional materials offer a platform to realize this concept but known 2D magnetic semiconductors are electrically insulating in their magnetic phase. An international team of researchers (USA – Columbia University, Brookhaven National Laboratory, Oak Ridge National Laboratory, Washington University, Japan) demonstrated tunable electron transport within the magnetic phase of the 2D semiconductor chromium sulfide bromide (CrSBr) and showed strong coupling between its magnetic order and charge transport. Exploiting the sensitivity of magnetoresistance to magnetic order, they uncovered […]
Heat storage: Scientists develop material that is stable, efficient, and eco-friendly
Phys.org March 29, 2022 Researchers in Germany have developed shape-stabilized phase change material which can absorb large amounts of heat by changing its physical state from solid to liquid. The stored heat is then re-released when the material hardens. They describe the steps involved in creating the structure of the material and how the different chemicals influence each other. Large panels of the material could be integrated into walls. These would then absorb heat during the sunny hours of the day and release it again later when the temperature goes down. Under the right conditions it could store up to […]
Evidence for exotic magnetic phase of matter
Science Daily February 22, 2022 An international team of researchers (USA – Brookhaven National Laboratory, University of Tennessee, Argonne National Laboratory, Oak Ridge National Laboratory, Switzerland, Japan, China) started their investigation of strontium iridium oxide (Sr3Ir2O7) starting at high temperature and gradually cooled the material. With cooling, the energy gap gradually narrowed. At 285 Kelvin electrons started jumping between the magnetic layers of the material but immediately formed bound pairs with the holes they’d left behind, simultaneously triggering the antiferromagnetic alignment of adjacent electron spins. They showed that their model comprehensively explains the experimental results. Understanding the connections between electrons’ […]
Mechanical metamaterials: Toughness and design criteria
Phys.org February 21, 2022 Rapid progress in additive manufacturing methods has created a new class of ultralight mechanical metamaterials with extreme functional properties. Their application is ultimately limited by their tolerance to damage and defects, but an understanding of this sensitivity has remained elusive. An international team of researchers (UK, USA – Virginia Polytechnical Institute and State University, UCLA, industry) used metamaterial specimens consisting of millions of unit cells, to show that not only is the stress intensity factor, as used in conventional elastic fracture mechanics, insufficient to characterize fracture, but also that conventional fracture testing protocols are inadequate. With […]
Scientists invent lead-free composite shielding material for neutrons and gamma-rays
Phys.org December 23, 2021 Through a series of intricate and comprehensive experiments researchers in China tested and certified the composite, modified-gadolinium oxide/boron carbide/high density polyethylene (Gd2O3/B4C/HDPE) as safe and effective to shield neutron and gamma rays. Fast neutrons collide with gadolinium (Gd) inelastically and collide elastically with hydrogen until they become thermal neutrons, finally, absorbed by high Z element Gd and boron. The experimental results show that the neutron shielding rate of the composite can reach 98% under the condition of 15 cm thickness in CF-252 environment. In cS-137 and CO-60 environments, the gamma shielding rates of the composite are […]
World’s smallest, best acoustic amplifier emerges from 50-year-old hypothesis
Nanowerk June 2, 2021 Researchers at Sandia National Laboratory have developed a heterogeneously integrated acoustoelectric material platform consisting of a 50 nm indium gallium arsenide epitaxial semiconductor film in direct contact with a 41° YX lithium niobate piezoelectric substrate. They demonstrated three of the main components of an all-acoustic radiofrequency signal processor: passive delay line filters, amplifiers, and circulators. Heterogeneous integration allows for simultaneous, independent optimization of the piezoelectric-acoustic and electronic properties, leading to the highest performing surface acoustic wave amplifiers in terms of gain per unit length and DC power dissipation. They described how the remaining components of an all-acoustic […]
Folding 2D materials gives them new properties useful for quantum communications
Nanowerk May 24, 2021 The use of 2D materials for nonlinear optics are limited by intrinsically small light-matter interaction length and (typically) flat-lying geometries. Researchers in the UK arranged 2D sheets of tungsten (WS2) in a new way to create a 3D arrangement they called a nanomesh. Its unique characteristics are the result of the specific synthesis process they developed. Only light with energy larger than the energy gap can interact with the material in a useful way. If new energy levels are introduced inside this energy gap, the doubling of frequency of the light that passes through the material […]
Titanium atom that exists in two places at once in crystal to blame for unusual phenomenon
Science Daily December 3, 2020 The crystalline solid BaTiS3 (barium titanium sulfide) is terrible at conducting heat. An international team of researchers (Caltech, University of Southern California, Stanford University, Oak Ridge National Laboratory, Washington University, Wright Patterson AFB, Argonne National Laboratory, South Korea) found that a wayward titanium atom that exists in two places at the same time is to blame. It provides a fundamental atomic-level insight into an unusual thermal property that has been observed in several materials. The work is of particular interest to researchers who are exploring the potential use of crystalline solids with poor thermal conductivity […]