Superconductors that work at temperatures much higher than absolute zero have befuddled scientists since they were discovered. A new theory might be about to change that.
The word “fractals” might inspire images of psychedelic colors spiraling into infinity in a computer animation. An invisible, but powerful and useful, version of this phenomenon exists in the realm of dynamic magnetic fractal networks.
Dustin Gilbert, assistant professor in the Department of Materials Science and Engineering, and colleagues have published new findings in the behavior of these networks—observations that could advance neuromorphic computing capabilities.
Their research is detailed in their article “Skyrmion-Excited Spin-Wave Fractal Networks,” cover story for the August 17, 2023, issue of Advanced Materials.
Glass might look and feel like a perfectly ordered solid, but up close its chaotic arrangement of particles more closely resemble the tumultuous mess of a freefalling liquid frozen in time.
Known as amorphous solids, materials in this state defy easy explanation. New research involving computation and simulation is yielding clues. In particular, it suggests that, somewhere in between liquid and solid states is a kind of rearrangement we didn’t know existed.
Continue reading “A Hidden State Between Liquid And Solid May Have Been Found” »
A team of researchers reports they have succeeded in disproving a long-held tenet of modern physics–that useful work cannot be obtained from random thermal fluctuations–thanks in part to the unique properties of graphene.
The microscopic motion of particles within a fluid, otherwise known as Brownian motion for its discovery by Scottish scientist Robert Brown, has long been considered an impossible means of attempting to generate useful work.
The idea had been most famously laid to rest decades ago by physicist Richard Feynman, who proposed a thought experiment in May 1962 involving an apparent perpetual motion machine, dubbed a Brownian ratchet.
A team of physicists and geologists at CEA DAM-DIF and Universit´e Paris-Saclay, working with a colleague from ESRF, BP220, F-38043 Grenoble Cedex and another from the European Synchrotron Radiation Facility, has succeeded in synthesizing a single-crystalline iron in a form that iron has in the Earth’s core.
In their paper published in the journal Physical Review Letters, the group describes how they used an experimental approach to synthesize pure single-crystalline ε-iron and possible uses for the material.
In trying to understand Earth’s internal composition, scientists have had to rely mostly on seismological data. Such studies have led scientists to believe that the core is solid and that it is surrounded by liquid. But questions have remained. For example, back in the 1980s, studies revealed that seismic waves travel faster through the Earth when traveling pole to pole versed equator to equator, and no one could explain why.
Diamond has long been the preferred material for quantum sensing, but its size limits its applications. Recent research highlights hBN’s potential as a replacement, especially after TMOS researchers developed methods to stabilize its atomic defects and study its charge states, opening doors for its integration into devices where diamond can’t fit.
Diamond has long held the crown in the realm of quantum sensing, thanks to its coherent nitrogen-vacancy centers, adjustable spin, magnetic field sensitivity, and capability to operate at room temperature. With such a suitable material so easy to fabricate and scale, there’s been little interest in exploring diamond alternatives.
However, this titan of the quantum domain has a vulnerability. It’s simply too large. Much like how an NFL linebacker isn’t the top pick for a jockey in the Kentucky Derby, diamond falls short when delving into quantum sensors and data processing. When diamonds get too small, the super-stable defect it’s renowned for begins to crumble. There is a limit at which a diamond becomes useless.
Recycling is now cheaper than mining.
Sandy visits the teams at RecycLiCo Battery Materials and Kemetco Research for an in-depth discussion on battery recycling and a tour of a facility that’s making this dream a reality.
Cellular solids are materials composed of many cells that have been packed together, such as in a honeycomb. The shape of those cells largely determines the material’s mechanical properties, including its stiffness or strength. Bones, for instance, are filled with a natural material that enables them to be lightweight, but stiff and strong.
Inspired by bones and other cellular solids found in nature, humans have used the same concept to develop architected materials. By changing the geometry of the unit cells that make up these materials, researchers can customize the material’s mechanical, thermal, or acoustic properties. Architected materials are used in many applications, from shock-absorbing packing foam to heat-regulating radiators.
Using kirigami, the ancient Japanese art of folding and cutting paper, MIT researchers have now manufactured a type of high-performance architected material known as a plate lattice, on a much larger scale than scientists have previously been able to achieve by additive fabrication. This technique allows them to create these structures from metal or other materials with custom shapes and specifically tailored mechanical properties.
With just a couple of “pieces of matter”—representations of one basic unit of a material—the new platform can create thousands of previously unknown morphologies, or structures, with the properties Amir Alavi specified.(Credit: Amir Alavi/U. Pittsburgh)
In a paper published in the journal Advanced Intelligent Systems, Amir Alavi, assistant professor of civil and environmental engineering in the University of Pittsburgh’s Swanson School of Engineering, outlines a platform for the evolution of metamaterials, synthetic materials purposefully engineered to have specific properties.
A thin film patterned with nanoantennas exhibits negative refraction of light, a useful feature for subwavelength imaging.
Materials that refract light the “wrong way” could be used to make optical lenses that can image objects smaller than visible wavelengths. So-called negative refraction has been demonstrated in thin films in which surface plasmons—collective charge oscillations—have been excited by a powerful laser. Now, an international team involving Purdue University, Indiana, the University of Glasgow, UK, and Imperial College London show that they can more efficiently achieve the same effect by placing an array of nanoscale antennas on the film.
