Science Daily July 5, 2018 A team of researchers in the US (UT Dallas, University of Illinois, University of Houston) has found high thermal conductivity of 1000 ± 90 W/m/K at room temperature in cubic boron arsenide grown through modified chemical vapor transport technique. The thermal conductivity is a factor of 3 higher than that of silicon carbide and surpassed only by diamond and the basal plane value of graphite. Boron arsenide could be a potential revolutionary thermal management material… read more. TECHNICAL ARTICLE
Tag Archives: Materials science
Manipulating single atoms with an electron beam
Eurekalert July 9, 2018 An international team of researchers (Austria, Norway, Belgium) used the advanced electron microscope to move single silicon atoms in graphene with atomic precision. They have taken the first steps towards automation by detecting the jumps in real time. The new results also improve theoretical models of the process by including simulations. In total, the researchers recorded nearly 300 controlled jumps. Silicon impurity could be moved back and forth between two neighboring lattice sites separated by one tenth-billionth of a meter, like flipping an atomic-sized switch. In principle, this could be used to store one bit of […]
A step closer to single-atom data storage
Phys.org July 10, 2018 Researchers in France found that the holmium atoms could retain record-breaking coercivity in a magnetic field exceeding 8 Tesla. Only at around 45K, the magnets began to spontaneously align themselves to the applied magnetic field. This showed that they can withstand relatively high temperature perturbations and might point to the way forward for running single-atom magnets at more commercially viable temperatures. Each atom can store a single bit of data that can be written and read using quantum mechanics. Such devices promise enormous data capacities… read more. Open Access TECHNICAL ARTICLE
New coatings make natural fabrics waterproof
Science Daily June 29, 2018 Conventional water-repellent coatings have been shown to persist in the environment and accumulate in our bodies. Researchers at MIT have developed a process that allows for iCVD deposition of durable, conformal short fluorinated polymers stabilized with a crosslinking agent resulting in high hydrophobicity, low liquid adhesion while maintaining initial substrate breathability. To further enhance the dynamic water repellency performance, the chemical treatment is combined with physical texturing making this combined approach a suitable candidate to meet the industrial needs. The process works on different kinds of materials including cotton, nylon, linen and paper, opening a […]
Electrospun sodium titanate speeds up the purification of nuclear waste water
Eurekalert June 27, 2018 Electrospun ion exchange fibres provide highly efficient and sustainable material for separation of trace pollutants, such as radionuclides and heavy metals. Researchers in Finland developed a process for electrospinning sodium titanate fibres and tested its ion exchange kinetics measurements. They found that by exploiting electrospun inorganic sub-micron fibres the ion exchanger mass required for a given capacity can be decreased significantly. With the help of this new method, waste water can be treated faster than before, and the environmentally positive aspect is that the process leaves less solid radio-active waste… read more. TECHNICAL ARTICLE
New carbon could signal step-change for the world’s most popular batteries
Phys.org June 25, 2018 An international team of researchers (China, India, UK, France) used ‘Eglinton homocoupling’ involving removing silicon from carbon-silicon groups to produce carbon to carbon links resulting in OSPC-1, an amorphous, very stable and highly conductive anode material for lithium-ion batteries. It does not form dendrites, able to store lithium ions at more than double the rate as graphite with high charging speeds and longer-lasting than graphite. They found no signs of deterioration after over 100 charging and discharging cycles. The method used by the team has the potential to be extended to other 3-D carbon materials… read […]
Scientists predict a new superhard material with unique properties
Phys.org June 14, 2018 An international team of researchers (Russia, Armenia, China) predicted new tungsten borides, some of which are promising hard materials that are expected to be stable in a wide range of conditions, according to the computed composition–temperature phase diagram. The new boron-rich compound WB5 is predicted to be superhard, with a Vickers hardness of 45 GPa, possess high fracture toughness of ∼4 MPa·m0.5, and thermodynamically stable in a wide range of temperatures at ambient pressure, and remains a high-performance material even at very high temperatures. Superhard substances have a broad scope of application in well drilling, machine […]
Silicon carbide LEDs make bright single photon sources
Physics World June 18, 2018 An international team of researchers (Germany, Japan, Sweden, South Korea) has discovered a variety of new colour centres in lateral p-i-n diodes made from a polytype (a crystal structure) of silicon carbide called 4H-SiC that contains naturally occurring divacancies. The newly-discovered centres emit non-classical light in the visible and near-infrared range. One type of defect can even be excited using electrical means. This means that it might be integrated into compact electronics devices as there would be no need for an additional bulky laser system to optically excite it. The work opens new directions both […]
Light-bending nano-patterns for LEDs
Nanowerk June 8, 2018 Researchers in Singapore designed and experimentally realized high efficiency beam deflecting and polarization beam splitting metasurfaces consisting of GaN nanostructures etched on the GaN epitaxial substrate itself. They demonstrated a polarization insensitive beam deflecting metasurface with 64% and 90% absolute and relative efficiencies, and the broad functionality that can be realized on this platform. The broadband response in the blue wavelength range of 430–470 nm. The nanophotonic platform of GaN shows the way to off- and on-chip nonlinear and quantum photonic devices working efficiently at blue emission wavelengths common to many atomic quantum emitters such as Ca+ […]
Researchers achieve almost instant magnetization of matter by light
Phys.org May 28, 2018 The magnetization of a material is associated with the spatial ordering of the spins of its constituent particles. An international team of researchers (Brazil, Austria) demonstrated that light resonant with the band gap forces the antiferromagnetic semiconductor EuSe to enter ferromagnetic alignment in the picosecond timescale. By increasing the light intensity, the whole of the illuminated region can be fully magnetized… read more. TECHNICAL ARTICLE