Material sciences

  • Splicing Together a Thin Film in Motion

    The principle of time-spliced imaging is depicted here for a simulated evolution of magnetic field lines from four rotating magnetic dipoles that have the same initial anti-ferromagnetic structure as the studied material, neodymium nickelate. The early frames in the time series pin down the set of possible reconstructions at later times, sharpening the image recovery by ruling out erroneous solutions. (c) Jörg Harms / MPSD

    Technology reliant on thin film materials has become ubiquitous in our everyday life. Control of the electronic properties of materials at the nanometer level is reflected in advances of computers, solar energy and batteries. The electronic behavior of thin films is heavily influenced by the contact with their surroundings, as exemplified by the recent discovery of 2D superconductivity at a thin film interface. However, information about how such entwined states come into existence is limited by the lack of tools capable of visualizing such buried interfaces.

  • Stagediving with Biomolecules Improves Optical Microscopy

    Microtubules, gliding through the optical near field (blue) of a nanostructured gold surface. The quantum dots (green) react to the local field by increasing their fluorescence rate. Graphic: Heiko Groß

    Physicists from Dresden and Würzburg have developed a novel method for optical microscopy. Using biological motors and single quantum dots, they acquire ultra-high-resolution images. The resolution of conventional optical microscopy is limited by the fundamental physical principle of diffraction to about one half of the wavelength of the light: If the distance between two objects is smaller than this so-called "diffraction limit", they can no longer be visually separated - their image appears "blurred ". To acquire optical images at the scale of few nanometers, this is clearly not sufficient.

  • Studying fundamental particles in materials

    Stimulated by special laser pulses Weyl-cones dance in a Dirac-fermion material on a laser-controlled path (loop). One cone includes right-handed, the other left-handed Weyl-fermions.  Jörg M. Harms/MPSD

    Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales.

    Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity to observe particle properties that have no realization in elementary particles.

  • Success in the 3D Bioprinting of Cartilage

    Stina Simonsson. Elin Lindström Claessen

    A team of researchers at Sahlgrenska Academy has managed to generate cartilage tissue by printing stem cells using a 3D-bioprinter. The fact that the stem cells survived being printed in this manner is a success in itself. In addition, the research team was able to influence the cells to multiply and differentiate to form chondrocytes (cartilage cells) in the printed structure. The findings have been published in Nature’s Scientific Reports magazine. The research project is being conducted in collaboration with a team of researchers at the Chalmers University of Technology who are experts in the 3D printing of biological materials. Orthopedic researchers from Kungsbacka are also involved in the research collaboration.

  • Superconductors Earn their Stripes

    By Mai-Linh Doan - self photo, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2911413

    Understanding high temperature superconductivity (high Tc) has been a long-standing challenge since its discovery in copper oxide compounds in 1986. A key issue in addressing this problem has involved the study of phases found near superconductivity, typically at temperatures in excess of Tc or at doping levels lower than those needed to achieve this state.

  • Superconductors through the inner city of Essen

    A superconducting cable requires much less space compared to traditional cables of equal transmission capacity.  © innogy SE

    To date, copper and aluminium cables carry the current into the city centres. Large substations lower the voltage to 10,000 volts and feed electricity into the distribution network. With compact high-temperature superconducting cables, this structure can be simplified. The BINE Projektinfo brochure "Superconductors for the medium-voltage network" (1/2017) describes a successful field test in Essen. The world's longest superconducting cable renders substation obsolete

  • Supported Liquid Metal Catalysts – a New Generation of Reaction Accelerators

    A diagram illustrating the processes at the catalytic surface of a liquid drop of gallium containing small amounts of palladium during the catalytic dehydrogenation of n-butane.  Image: FAU/Mathias Grabau and Florian Maier

    Catalysts are agents that initiate chemical reactions, speed them up or significantly increase the yield of the desired product. New and improved catalysts are thus considered the key to creating more sustainable and efficient production processes in the chemical industry. In a joint research project, five professors at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and their teams have recently discovered how to bypass the known drawbacks of the technical catalysts that are currently in use by means of a new material concept that makes the creation of significantly more efficient catalysts possible.

  • Tailor-Made Membranes for the Environment

    Transmission electron microscope image of the membrane, provided by the Ernst Ruska-Centre. The two phases for proton and electron conduction are marked in colour. Forschungszentrum Jülich

    Jülich, 30 November 2016 – The combustion of fossil energy carriers in coal and gas power plants produces waste gases that are harmful to the environment. Jülich researchers are working on methods to not only reduce such gases, but also utilize them. They are developing ceramic membranes with which pure hydrogen can be separated from carbon dioxide and water vapour. The hydrogen can then be used as a clean energy carrier, for example in fuel cells. The researchers have now been able to increase the efficiency of these membranes to an unprecedented level. Their research results were published in Scientific Reports.

  • Tandem Solar Cells – Record Efficiency for Silicon-based Multi-junction Solar Cell

    Tandem solar cell made of silicon and III-V semiconductor materials, a more energetically efficient use of the solar spectrum is possible, compared to conventional solar cells available today. © Fraunhofer ISE/ A. Wekkeli

    Silicon solar cells dominate the photovoltaic market today but the technology approaches the theoretical maximum efficiency that can be achieved with silicon as the only absorber material. Tandem solar cells, on the other hand, combine several absorber materials, enabling a better energetic use of the solar irradiance spectrum. Due to their higher efficiency potential, tandem solar cells have a promising future. After intensive research, scientists at Fraunhofer ISE in cooperation with partners have achieved a new efficiency record of 22.3 percent for a multi-junction solar cell made of silicon and III-V semiconductor materials.

  • The Coldest Chip in the World

    A chip with a Coulomb blockade thermometer on it is prepared for experiments at extremely low temperatures. (University of Basel, Department of Physics)

    Physicists at the University of Basel have succeeded in cooling a nanoelectronic chip to a temperature lower than 3 millikelvin. The scientists from the Department of Physics and the Swiss Nanoscience Institute set this record in collaboration with colleagues from Germany and Finland. They used magnetic cooling to cool the electrical connections as well as the chip itself. The results were published in the journal Applied Physics Letters. Even scientists like to compete for records, which is why numerous working groups worldwide are using high-tech refrigerators to reach temperatures as close to absolute zero as possible. Absolute zero is 0 kelvin or -273.15°C. Physicists aim to cool their equipment to as close to absolute zero as possible, because these extremely low temperatures offer the ideal conditions for quantum experiments and allow entirely new physical phenomena to be examined.

  • The Fine Art of Tailoring Materials

    Siemens researchers subject generator bars to a potential difference of over 70,000 volts in order to test their capacity. Spectacular discharges occur during the process.

    The electronics industry requires plastics with precisely defined properties. Siemens is developing technologies that make it possible to combine materials in such a way as to meet increasingly specific demands. Each of us is in contact with plastics every day. In toothbrushes, ballpoint pens, smartphones — there’s no getting away from plastic, or, as the experts put it, synthetic polymers. Many of these everyday plastics have straightforward properties such as light weight, flexibility or hardness. Plastics for use in industry, especially in electrical engineering, require much more specialized properties. These range from transparency and magnetic qualities to the ability to withstand temperature extremes, and the ability to conduct – or minimize conduction of – heat or electricity.

  • The Future of Ultrafast Solid-State Physics

    Light waves and their electromagnetic fields oscillate at rates on the order of a million billion times per second. In principle then, light can be employed to modulate the behavior of charged particles, such as electrons, in solid-state matter at similar rates. Photo: Alexander Gelin

    In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies. Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort light pulses in the infrared and visible regions of the spectrum.

  • The Hidden Nano Power Switch: Kiel Researchers Discover Switching Function in Molecular Wire

    Torben Jasper-Tönnies placed a single atom at the tip of the scanning tunnelling microscope and was able to join a tiny wire with a diameter of just one atom to an electrical circuit. Photo: Siekmann/CAU

    The increasing miniaturisation in electronics will result in components which consist of only a few molecules, or even just one molecule. An international research team from Kiel University (CAU) and the Donostia International Physics Center in San Sebastián/Spain, has developed a molecule integrating a wire with a diameter of only a single atom. They discovered that the current can be regulated via this molecular wire. It works like a nano power switch, and makes the use of molecular wires in electronic components at the nano scale feasible. The research team’s findings appeared in the scientific journal Physical Review Letters.

  • The link between nanostructured electrode materials and Samsung’s debacle

    Schematic of lithium-air battery charge and discharge cycles.

    As recently has been announced, the South Korean multinational electronics company SΛMSUNG had to recall its flagship Galaxy Note 7 smartphone with the reason that battery problems cause the “explosion” of the phones during or after charging.
    In regard to the recent events, the German news site heise online published an interview with battery researcher Bai-Xiang Xu from the Technical University Darmstadt in which she explains the technical background of the Note 7 debacle.

  • The nanostructured cloak of invisibility

    Substrate with 450 nm nanopillars (left) compared to an unstructured reference (right). The top set of images were taken at an observation angle of 0°, the bottom set of images at 30°. © Zhaolu Diao

    Most lenses, objectives, eyeglass lenses, and lasers come with an anti-reflective coating. Unfortunately, this coating works optimally only within a narrow wavelength range. Scientists at the Max Planck Institute for Intelligent Systems in Stuttgart have now introduced an alternative technology. Instead of coating a surface, they manipulate the surface itself. By comparison with conventional procedures, this provides the desired anti-reflective effect across a wider wavelength range. But more than this, it largely increases the light transmittance through surfaces.

  • The Role of Sodium for the Enhancement of Solar Cells

    Dr. Torsten Schwarz, postdoctoral researcher at the MPIE, analyzed the local clustering and gradients of sodium with the atom probe (seen in the image). Max-Planck-Institut für Eisenforschung GmbH

     

    Green energy gained by photovoltaic amounts ca. 6% of Germany’s gross power production . The most common solar cells currently used are made out of silicon. So-called CIGS, solar cells out of copper, indium, gallium and selen (Cu(In,Ga)(S,Se)2, are a promising alternative with an efficiency of ca. 23%, which is the conversion rate of light to electricity. In comparison to conventional silicon solar cells, CIGS consumes less material and production energy and are thus cheaper in production and environmentally friendly.

  • The Slipperiness of Ice Explained

    In the experiments, a steel ball slides over the ice surface which consists of rapidly tumbling mobile water molecules that are only loosely bounded to the underlying ice. © Nagata/MPI-P

    Everybody knows that sliding on ice or snow, is much easier than sliding on most other surfaces. But why is the ice surface slippery? This question has engaged scientists for more than a century and continues to be subject of debate. Researchers from AMOLF, the University of Amsterdam and the Max Planck Institute for Polymer Research (MPI-P) in Mainz, have now shown that the slipperiness of ice is a consequence of the ease with which the topmost water molecules can roll over the ice surface.

  • The Stacked Colour Sensor

    Original image (left) and corresponding portrayal of the red, green and blue regions, and a composite image. Empa

    Red-sensitive, blue-sensitive and green-sensitive colour sensors stacked on top of each other instead of being lined up in a mosaic pattern - this principle could allow image sensors with unprecedented resolution and sensitivity to light to be created. However, up to now, the reality hasn't quite met expectations. Researchers from Empa and ETH Zurich have now developed a sensor prototype that absorbs light almost optimally - and which is also cheap to produce.

  • Thermoelectric Cooling Gets Fit for Micro Technology

    Array of micro-thermoelectric devices with a packing density of about 5,000 pieces per square centimeter. The free-standing design reduces thermo-mechanical stress. Leibniz-Institut für Festkörper- und Werkstoffforschung

    Scientists at Leibniz Institute for Solid State and Materials Research Dresden (IFW) have significantly improved the processing of thermoelectric devices so that they become quicker, more reliably and suitable for integration in microchips. This represents a decisive step towards the broad application of thermoelectric components in micro technology. Thermoelectric materials can convert heat into electricity or, vice versa, can be used as environmentally friendly cooling elements. In many processes in everyday life and in industry, energy losses occur in form of waste heat, which can be converted by thermoelectric generators into electrical energy. This also provides an additional power source in these systems.

  • Three Kinds of Information from a Single X-Ray Measurement

    The physicists Dr Andreas Johannes (l.) and Prof. Dr Carsten Ronning in a laboratory at the Institute of Solid State Physics of Friedrich Schiller University Jena. (Photo: Jan-Peter Kasper/FSU Jena)

    Physicists at Friedrich Schiller University Jena (Germany) and partners develop new measurement method for active nanoscale components. Jena (Germany, 08.12.2017) Whatever the size of mobile phones or computers are, the way in which such electronic devices operate relies on the interaction between various materials. For this reason, engineers as well as researchers need to know exactly how specific chemical elements inside a computer chip or a transistor diode behave, and what happens when these elements bond.