Whether it will compete for the title of a girls best friend remains to be seen but the element osmium can already challenge diamond in at least one respect: stiffness. According to a report published in the current issue of Physical Review Letters, osmium can withstand compression better than any known material. The results provide a potentially new lead in the search for superhard materials.
Diamonds ability to resist scratches, dents and chipping--in short, its hardness--makes it an ideal choice for tips in industrial strength machines. A related quality that is easier to calculate than hardness is an elements resistance to compression, as known as its bulk modulus. The properties are interrelated because the stiffest materials also tend to be the hardest ones. But even though osmium is much softer than diamond, initial estimates of its bulk modulus indicated a similar value to that of diamond.
Hyunchae Cynn and colleagues at Lawrence Livermore National Laboratory thus set out to test the property experimentally. They squeezed osmium powder under 600,000 atmospheres of pressure and calculated changes in the spacing between atoms in the sample using x-ray diffraction patterns. The team reports that osmiums bulk modulus is 462 gigapascals (GPa) as compared to diamonds 443 GPa. "It is intriguing that a light, covalently bonded element such as diamond and a heavy, metallic element such as osmium, with very different chemical bonding, would both have large values of the bulk modulus," the authors note. They conclude that related compounds such as transition metal carbides, nitrides and oxides could be sources of new superhard materials. --
Sarah Graham | News in Brief
New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State
Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology
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...
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22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy