The same team of researchers discovered intermediate phases seven years ago in amorphous or disordered materials where networks are covalently bonded.
The team’s results are presented in “Fast-ion conduction and flexibility of glassy networks,” to be published this spring in Physical Review Letters.
“We find that when networks become flexible their electrical conductivity increases precipitously,” says Deassy Novita. “Now we will be able to chemically tune these materials for specific applications. For example, the batteries implanted in patients who have heart pacemakers make use of a solid electrolyte.”
Novita is a third-year graduate student working in the lab of Punit Boolchand, professor of electrical engineering in the University of Cincinnati’s College of Engineering. Originally from Indonesia and now a U.S. citizen, Novita began the ground-breaking research as part of her doctoral thesis.
"This system has been studied by about 35 groups all over the world over the past two decades. We are the first to make these samples in a ‘dry’ state,” says Boolchand. “Most people who studied these materials produced them unwittingly in the laboratory ambient environment where the relative humidity is typically 50%, and that leads to samples that are — so to speak — in a ‘wet’ state. By special handling of the materials, we were able to produce them in a dry state, where we can see the intrinsic behavior of these materials.”
"The intrinsic behavior shows samples to exist in three elastic domains," Boolchand explains. "In the first domain, at low AgI (silver iodide) content (less than 9.5%) they form networks that are rigid but stressed. In the second domain, called the “intermediate phase,” at a slightly higher content of AgI (9.5 to 37.8%), they form networks that are rigid but unstressed. And finally in the third domain, at AgI content of 37.8% and higher, their networks become flexible."
The UC research team showed for the first time that such intermediate phases also exist in networks that are ionically conducting. In the flexible phase of these materials, “silver ions move like fish through water,” Boolchand says.
The next step in their research will be to understand why traces of water change the behavior of these electrolytes so drastically and to understand if the behavior observed here of three elastic domains is a general feature of all electrolyte glasses or is it peculiar to this very well studied material.
“We think the behavior will be observed in general in solid electrolytes,” says Boolchand.
The current work was supported by a National Science Foundation grant.
Published in “Fast-ion conduction and flexibility of glassy networks,” Physical Review Letters.Authors:
M.Malki, Centre de Recherche sur les Matériaux a Haute Température, Université d’Orléans, France
M. Micoulaut, Laboratoire de Physique Théorique de la Matière Condensée, Université Pierre et Marie Curie, Paris, France
Wendy Beckman | EurekAlert!
Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas
22.09.2017 | Forschungszentrum MATHEON ECMath
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy