- The new knowledge explains exactly why some thermoelectric materials can have the desired low thermal conductivity without degrading the electrical properties. This can be crucial for the conversion of wasted heat, for example, from vehicle exhaust emissions.
Leading car manufacturers are now working to develop this possibility and the first models are close to production. The technology is expected to give the cars considerably improved fuel economy, explains Bo B. Iversen, Professor at iNANO at the University of Århus. The new knowledge can also contribute to the development of new cooling methods, so that one avoids the most common, but very environmentally damaging greenhouse gas (R-134a). All of which is a gain for the environment.
In the Nature Materials article the researchers have studied one of the most promising thermoelectric materials in the group of clathrates, which create crystals full of ‘nano-cages’.
- By placing a heavy atom in each nano-cage, we can reduce the crystals’ ability to conduct heat. Until now we thought that it was the heavy atoms random movements in the cages that were the cause of the poor thermal conductivity, but this has been shown to not be true, explains Asger B. Abrahamsen, senior scientist at Risø-DTU.
The researchers have used the technique of neutron scattering, which gives them opportunity to look into the material and see the atoms’ movements.
- Our data shows that, it is rather the atoms’ shared pattern of movement that determines the properties of these thermoelectric materials. A discovery that will be significant for the design of new materials that utilize energy even better, explains Kim Lefmann, associate professor at the Nano-Science Center, the Niels Bohr Institute at the University of Copenhagen.
Rikke Bøyesen | alfa
Laser sensor LAH-G1 - optical distance sensors with measurement value display
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Engineers find better way to detect nanoparticles
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Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
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Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
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An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
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A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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