Science Daily October 28, 2021 Researchers in Japan have created functional materials with advanced three-dimensional nanostructures that conduct electricity based on the idea that unique reactions occur at interfaces of water and oil. As they spread a solution containing organic linkers on aqueous solution of metal ions the substances begin assembling their components in a hexagonal arrangement forming nanosheets where the liquid and air meet. They used two barriers to compress the nanosheets into more dense and continuous state. The process produced thin nanosheets with highly organized crystalline structures, tightly ordered crystals also indicated the electrical properties of the material. […]
Tag Archives: Advanced materials
Shape-shifting materials with infinite possibilities
Phys.org October 22, 2021 Researchers at Harvard University have created structural materials, they call totimorphic materials, that have an arbitrary range of shape-morphing capabilities. By having a neutrally stable unit cell they could separate the geometry of the material from its mechanical response at both the individual and solved the problem of balancing the needs of conformability and rigidity. They connected individual unit cells with naturally stable joints, building 2-D and 3-D structures from individual totimorphic cells. Using both mathematical modeling and real-world demonstrations they showed the material’s shape-shifting ability. One single sheet of totimorphic cells could curve up, twist […]
A rare feat: Material protects against both biological and chemical threats
Science Daily October 8, 2021 The development of a multifunctional protective textile is still behind to supply adequate protection for the public. An international team of researchers (Hong Kong, USA – Northwestern University, US Army Aberdeen Proving Ground, the Netherlands) has designed multifunctional and regenerable N-chlorine based biocidal and detoxifying textiles using a robust zirconium metal–organic framework (MOF), UiO-66-NH2, as a chlorine carrier which can be easily coated on textile fibers. The fibrous composite exhibited rapid biocidal activity against both Gram-negative bacteria (E. coli) and Gram-positive bacteria (S. aureus) with up to a 7 log reduction within 5 min for […]
Induced flaws in quantum materials could enhance superconducting properties
Science Daily October 4, 2021 The properties of quantum materials are commonly tuned using experimental variables such as pressure, magnetic field, and doping. An international team of researchers (USA – University of Minnesota, Oak Ridge National Laboratory, Argonne National Laboratory, Croatia, China) has shown that compressive plastic deformation induces low-dimensional superconductivity well above the superconducting transition temperature (Tc) of undeformed SrTiO3, with evidence of possible superconducting correlations at temperatures two orders of magnitude above the bulk Tc. The enhanced superconductivity is correlated with the appearance of self-organized dislocation structures. They observed deformation-induced signatures of quantum-critical ferroelectric fluctuations and inhomogeneous ferroelectric […]
Skyrmion research: Braids of nanovortices discovered
Phys.org October 6, 2021 Braided structures are commonly seen in nature. An international team of researchers (Germany, Sweden, China) has discovered that such structures exist on the nanoscale in alloys of iron and the metalloid germanium. These nanostrings are each made up of several skyrmions that are twisted together to a greater or lesser extent, rather like the strands of a rope. Each skyrmion itself consists of magnetic moments that point in different directions and together take the form of an elongated tiny vortex. The length of the magnetic structures is limited only by the thickness of the sample. Earlier […]
Tiny lasers acting together as one: Topological vertical cavity laser arrays
Phys.org September 24, 2021 Vertical-Cavity Surface-Emitting Lasers (VCSEL) device has miniscule size of only a few microns, which sets a stringent limit on the output power it can generate. An international team of researchers (Israel, Germany) utilized the concepts of topological photonics with VCSELs that emit light vertically, while the topological process responsible for the mutual coherence and locking of the VCSELs occurs in the plane of the chip. It resulted in a powerful but very compact and efficient laser, not limited by a number of VCSEL emitters, and undisturbed by defects or altering temperatures. The topological principle of this […]
Just by changing its shape, scientists show they can alter material properties
Nanowerk September 13, 2021 An international team of researchers (USA – Argonne National Laboratory, University of Chicago, Israel) explored confined transport using a patterned structure in titania films, with feature sizes of 11–20 nm. They described how confinement changes the competing charge transport mechanisms, the patterned antidot array leads to displacement fields and confines the charge density that results in modified and emergent electron transport with an increase in conductivity. This emergent behavior can be described by considering electron interference effects. Characterization of the charge transport with electron holography and impedance spectroscopy, and through comparison with modeling, showed that nanoscale […]
Triangular honeycombs: Physicists design novel quantum material
Nanowerk September 14, 2021 Using molecular beam techniques researchers in Germany succeeded in depositing a single layer of indium atoms as triangular lattice on a silicon carbide crystal as support resulting in indenene. The relevant electrons occupy free space in between the indium positions. Their charge fills the “negative” of the triangular indium lattice which is actually a honeycomb lattice. Unlike graphene, indenene needs not to be cooled down to ultra-low temperatures to manifest its properties as a topological insulator. The simple structure of indenene represents at the same time a challenge: as soon as the single layer of indium […]
Graphene valleytronics: Paving the way to small-sized room-temperature quantum computers
Phys.org September 8, 2021 Electrons in two-dimensional hexagonal materials have an extra degree of freedom that can be used to encode and process quantum information. An international team of researchers (India, Germany) demonstrated that both valley-selective excitation and valley-selective high-harmonic generation can be achieved in pristine graphene by using a combination of two counter-rotating circularly polarized fields, the fundamental and its second harmonic. Controlling the relative phase between the two colors allowed them to select the valleys where the electron–hole pairs and higher-order harmonics are generated. They described an all-optical method for measuring valley polarization in graphene with a weak […]
Researchers reveal a novel metal where electrons flow with fluid-like dynamics
Phys.org September 6, 2021 An international team of researchers (USA -Boston College, Florida State University, UT Dallas, Switzerland) found that a strong interaction between electrons and phonons alters the transport of electrons from the diffusive, or particle-like, to hydrodynamic, or fluid-like, regime in a synthesis of Niobium and Germanium (NbGe2). Electrical resistivity measurements showed a higher-than-expected mass for electrons, and X-ray diffraction revealed the crystal structure of the material. The mass of electrons in all trajectories was three times larger than the expected value. The strong electron-phonon interaction was responsible for the heavy electron behavior. In future work the team […]