| 13 Sep 2016 |
Microscopists detect quasi-chiral walls in ferroelectric materials
Jülich, 13 September 2016 - The atomic structure of ferroelectric materials is more diverse than previously assumed. An international research team made this discovery through experiments with electron microscopes carried out at the Ernst Ruska-Centre (ER-C) in Jülich. The ER-C is a leading centre for ultra-high-resolution electron microscopy. Their discovery could open up new fields of applications for a particular class of polarised crystals: so-called ferroelectric materials. The researchers believe these applications could range from the development of miniaturized pressure sensors and the tiniest of transistors through to highly integrated storage media (Nature Communications, DOI: 10.1038/ncomms12385).
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Néel-like domain walls in ferroelectric Pb(Zr,Ti)O3 single crystals;
Xiankui Wie et al.;Nature Communications 7, Veröffentlichung vom 19. August 2016, DOI: 10.1038/ncomms12385
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| 20 Oct 2016 |
Neutron Scattering: Rethinking the Role of Magnetic Fluctuations in High Temperature Superconductivity
Jülich, 20 October 2016 - Since the discovery of high temperature superconductivity, researchers have tried to find out why these materials already become superconducting at comparatively high temperatures. Neutron scattering experiments at the outstation of the Jülich Centre for Neutron Science (JCNS) at the Heinz Maier-Leibnitz Zentrum in Garching near Munich as well as at the NIST Center for Neutron Research (NCNR) in Gaithersburg, Maryland, USA, suggest a need to rethink the role of magnetic fluctuations in the formation of this phenomenon. This kind of magnetic excitation occurs in all unconventional superconductors close to the transition temperature. Two models are being considered as possible causes; the outcome of the international team’s experiments are in good agreement with one of them.
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Song, Y. et al.; Robust upward dispersion of the neutron spin resonance in the heavy fermion superconductor Ce1−xYbxCoIn5.
Nat. Commun. 7:12774 doi: 10.1038/ncomms12774 (2016)
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| 20 Oct 2016 |
Faster Data Storage Thanks to Molecular Magnets Containing Rare Earth Materials?
Jülich, 20 October 2016 - Molecular magnets made from metal atoms and organic molecules could one day enable the development of storage media with greater capacity and faster, more energy-efficient information processors. Until now, rare earth metals were regarded as unsuitable for this purpose, as the electrons responsible for their magnetic properties are “hidden” in 4f orbits, which are difficult to access for studies or technical use. Theoretical studies performed in Jülich now explain how strong organic molecules can modify the chemical environment around rare earth metals. As a result, orbits are able to form that unite characteristics of atomic and 5d+4f hybrid orbitals, and are more easily accessible for studies using e.g. scanning tunnelling microscope measurements, or in technical applications.
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Sub-molecular modulation of a 4f driven Kondo resonance by surface-induced asymmetry, Nature Communications 7, 12785 (2016); DOI: 10.1038/ncomms12785
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| 20 Oct 2016 |
Surprising Insight into the World of Atomic Nuclei
Jülich, 20 October 2016 - How do neutrons and protons combine to form atomic nuclei? A new computer simulation has produced a surprising result to this question: if one single parameter was minimally altered in the simulation, it had fundamental effects on the structure of the nuclei. Our universe might therefore look quite different under slightly altered conditions. Alongside the University of Bonn, Forschungszentrum Jülich, Ruhr University Bochum, and two US universities also participated in the study. The results were published in the journal Physical Review Letters.
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Serdar Elhatisari, Ning Li, Alexander Rokash, Jose Manuel Alarcon, Dechuan Du, Nico Klein, Bing-nan Lu, Ulf-G. Meißner, Evgeny Epelbaum, Hermann Krebs, Timo A. Lähde, Dean Lee, Gautam Rupak: Nuclear binding near a quantum phase transition; Physical Review Letters; DOI: 10.1103/PhysRevLett.117.132501
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| 27 Oct 2016 |
Neutrons Verify New Quantum State
Jülich, 26 October 2016 - An international research team has proved the existence of spin-spirals in a quantum liquid. They emerge at low temperatures from the magnetic moments ("spins") of manganese scandium thiospinel single crystals (MnSc2S4). Neighbouring spins fluctuate here collectively as spirals, but when spatial distances are involved, they do not take on any particular order, just as water molecules will only form structures with neighbouring water molecules. Proof of this so-called "spiral spin-liquid" was achieved with the help of polarized diffuse neutron scattering on an instrument of the Jülich Centre for Neutron Science (JCNS) at its outstation at the Heinz Maier-Leibnitz Zentrum.
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S. Gao et al.;
Spiral Spin-Liquid and the emergence of a vortex-like state in MnSc2S4;
Nature Physics (2016), Published online 24 October 2016, DOI:10.1038/nphys3914
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| 16 Nov 2016 |
Improved Insight into the Structure of Lipid Membranes
Jülich, November 2016 - Neutron reflectometry is one of the most suitable methods for investigating the structure of lipid membranes in model systems. These model systems are more easily prepared and experimentally controlled than natural lipid membranes, which are an important integral part of animal and plant cells. A scientist from the Jülich Centre for Neutron Science has now presented a method which delivers more precise results and should pave the way for studying membranes of a more complex nature. The method combines the advantages of neutron reflectometry and molecular dynamic simulations.
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Alexandros Koutsioumpas;
Combined Coarse-Grained Molecular Dynamics and Neutron Reflectivity Characterization of Supported Lipid Membranes;
J. Phys. Chem. B, Article ASAP, DOI: 10.1021/acs.jpcb.6b05433, Publication Date (Web): October 17, 2016
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| 16 Dec 2016 |
Focused Interactions Important for Protein Dynamics
Jülich, 14 December 2016 - Many biological processes in cells function solely due to the phenomenon of diffusion. This ensures that particles are able to move randomly and aimlessly on the basis of their thermal energy alone. In this way, protein molecules get into close enough proximity to each other to, for example, carry out metabolic processes only achievable when acting together. A team of international researchers has now shown that weak attraction forces between proteins can enormously influence diffusion, if the protein molecules are as densely concentrated as under natural conditions in living cells.
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Dramatic influence of patchy attractions on short-time protein diffusion under crowded conditions;
Saskia Bucciarelli, Jin Suk Myung, Bela Farago, Shibananda Das, Gerard Vliegenthart, Olaf Holderer, Roland G. Winkler, Peter Schurtenberger, Gerhard Gompper, Anna Stradner;
Science Advances 2: e1601432 (2016); DOI: 10.1126/sciadv.1601432
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