Nanowerk September 12, 2018 An international team of researchers (China, USA – Boston College, Princeton University, Lawrence Berkeley National Laboratory, Taiwan) arranged atoms on the surface of crystals in many different patterns on ferromagnet to explore the associated phenomena. The electrons hovering above their atoms aligned in a straight line, with two-fold symmetry ignoring the lattice symmetry. When a magnetic field was applied they could turn one line in any direction they chose rotating the line of electrons just by controlling the magnetic field around them. Anisotropy was 100 times more than what theory predicts. The findings open enormous possibilities […]
Category Archives: Advanced materials
Multifunctional carbon fibres enable massless energy storage
Physics World September 7, 2018 Carbon fibres’ microstructural designs have been generated to realise a targeted mechanical property. An international team of researchers (Italy, Sweden, France) compared the microstructure and electrochemical performance for two types of commercial carbon fibre, middling mechanical properties and the hardest hitters in terms of structural strength. They found that the intermediate strength carbon fibres were much less organised but still had such high mechanical properties that even smaller crystals might still get good mechanical properties. According to the researchers exploiting the electrochemical properties of carbon fibres could drop device masses by as much as 50%… […]
Cannibalistic materials feed on themselves to grow new nanostructures
Science Daily August 31, 2018 A team of researchers in the US (Oak Ridge National Laboratory, Pennsylvania State University, Drexel University) has shown that by thermal exposure and electron-beam irradiation, hexagonal TiC single adlayers form on defunctionalized surfaces of Ti3C2 MXene at temperatures above 500 °C, generating new 2D materials Ti4C3 and Ti5C4, with the substrate being the source material. The work could lead to the development of bottom-up synthesis methods using substrates terminated with similar hexagonal-metal surfaces, for controllable synthesis of larger-scale and higher quality single-layer transition metal carbides… read more. Open Access TECHNICAL ARTICLE
Dual-layer solar cell sets record for efficiently generating power
Nanowerk August 31, 2018 The combination of hybrid perovskite and Cu(In,Ga)Se2 (CIGS) has the potential for realizing high-efficiency thin-film tandem solar cells because of the complementary tunable bandgaps and excellent photovoltaic properties of these materials. Researchers in Japan used nanoscale interface engineering of the CIGS surface and a heavily doped poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) hole transport layer between the subcells that preserves open-circuit voltage and enhances both the fill factor and short-circuit current. The solar cell achieved a 22.43% efficiency, and unencapsulated devices under ambient conditions maintained 88% of their initial efficiency after 500 hours of aging under continuous 1-sun illumination… read […]
Scientists predict superelastic properties in a group of iron-based superconductors
Science Daily August 30, 2018 By performing pressure simulations within density functional theory for the family of iron-based superconductors an international team of researchers (Germany, USA – Iowa State University) predicts that in these systems the appearance of two consecutive half-collapsed tetragonal transitions at pressures Pc1and Pc2. They identify clear trends of critical pressures and discuss the relevance of the collapsed phases in connection to magnetism and superconductivity. Not only does this study have implications for properties of magnetism and superconductivity, it may have much wider application in room-temperature elasticity… read more. TECHNICAL ARTICLE
Scientists design material that can store energy like an eagle’s grip
Science Daily August 9, 2018 Researchers in the UK have redesigned auxetic materials with smooth curves which distribute the forces and make repeated deformations possible. A major problem for materials exposed to harsh conditions, such as high temperature, is their expansion. The new material can be designed so its expansion properties continuously vary to match a gradient of temperature farther and closer to a heat source. It will be able to adjust itself naturally to repeated and severe changes. The work lays the basis for designs of lightweight 3D supports, which also fold in specific ways and store energy which […]
Bacteria-fighting polymers created with light
Phys.org August 14, 2018 Researchers in the UK have developed a way to synthesize large libraries of polymers to make screening for antimicrobial activity faster, and without the need to use sealed vials. By using multiple ‘building blocks’ in their polymers, new antimicrobials were identified – some of which appear to inhibit bacteria growth, contrary to predictions. They found that the best materials do not seem to break apart the bacteria as we predicted, but rather inhibit their growth. The benefit of the method is that it allows screening of hundreds of different structures, enabling the researchers to ‘go fishing’ […]
PhD student develops spinning heat shield for future spacecraft
Phys.org August 9, 2018 Researchers in the UK have developed a flexible, foldable heat shield that is shaped like a skirt and spins like a sycamore seed. The material is lightweight strong and has high temperature tolerance. The shield is stitched along a special pattern that allows it to spin up during flight, inducing centrifugal force. Planets with atmospheres, such as Earth and Mars, allow spacecraft to utilize aerodynamic drag to slow down and the prototype’s design uses this to enable atmospheric entry. The prototype is lightweight and flexible enough for use on smaller satellites… read more.
Nanotube ‘rebar’ makes graphene twice as tough
Science Daily August 4, 2018 In 2014 Rice University researchers developed Rebar graphene that consists of CNTs embedded in graphene. An international team of researchers (USA – Rice University, University of Maine, Brown University, China) implemented a “dry” transfer technique to test the freely suspended rebar graphene under uniaxial tension mode. Combined experiments and molecular dynamics simulations confirmed that the embedded CNTs divert and bridge the propagating crack and provide a toughening mechanism for the material. This is a promising extrinsic toughening strategy for 2D materials and provides mechanistic insights into the fracture process of graphene hybrid material. The experiments […]
An insect-inspired drone deforms upon impact
Science Daily July 26, 2018 An international team of researchers (Switzerland, Japan) has developed an origami structure which consists of a prestretched elastomeric membrane, akin to the soft resilin joints of insect wings, sandwiched between rigid tiles, akin to the rigid cuticles of insect wings. The dual-stiffness properties of the structure are validated by using the origami as an element of a quadcopter frame that can withstand aerodynamic forces within its flight envelope but softens during collisions to avoid permanent damage… read more. TECHNICAL ARTICLE