Using biominerals as an inspiration, Livermore physicist Jim De Yoreo and his LLNL research team have determined a key factor in how to manipulate the shapes of crystals.
In a series of experiments using an atomic force microscope, De Yoreos team and that of Patricia Dove, a geoscientist from Virginia Polytechnic Institute and State University, used four different biomolecules to study their effects on the dynamics of atomic steps during crystallization. They set out to test a two-decade-old model of crystal-shape modification believed to be at odds with classic theories of crystal growth. Their results appear in the Nov. 19 issue of the journal, Science.
The main focus of the work was on the mineral calcite, which has more than 300 identified crystal forms that can combine to produce at least a thousand different crystal variations. Crystals can form a thousand different shapes by combining the basic forms of the positive rhombohedron (a prism with six faces, each a rhombus), negative rhombohedron, steeply, moderately and slightly inclined rhombohedrons, various scalahedrons, prism and pinacoid. De Yoreo and Dove first determined that when combined with magnesium, the corners formed by the intersection of atomic steps flatten and roughen, leading to flattening of the crystals corners and elongation and roughening of the crystal shape.
Anne M. Stark | EurekAlert!
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For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
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13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences