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Just a Little Spice Adds A Lot to the Mix

Scientists have discovered a way to improve the energy conversion efficiency of a key green material by 25%. Thermoelectric materials can convert waste heat into electricity, but the low efficiency of existing thermoelectric materials limits their widespread use.  Researchers found that by adding a little bit (just 1%) of the rare earths cerium or ytterbium to material made from silver, antimony, germanium and tellerium can make a huge difference.

Unconventional Field Expulsion

Researchers have found that two iron arsenide superconductors exhibit novel behavior. When a material is cooled below its superconducting transition temperature in an applied magnetic field, it expels some portion of that field. Exactly how this Meissner effect occurs depends on the physical properties of the sample, the type of superconductivity, and the experimental conditions. However, for all superconductors field expulsion is determined by the strength of the Meissner currents, which peak at some critical field value.

Strength without Compromise

Scientists have discovered a way to make strong materials that are also ductile. One of life’s classic problems is that whenever a metal or alloy is altered to make it stronger, it loses its ability to deform – it becomes brittle, so its eventual failure is both unheralded and catastrophic. Nanostructured materials have shown great improvements in strength over their conventional counterparts, but until now, they have also typically been more brittle.

Primal Magnetism

Quantum critical transitions take place at absolute zero and their occurrence can provide fundamental information about the onset of magnetism.  Studying quantum criticality is challenging, however, because we cannot make measurements at absolute zero, and we must rely on less distinct changes in the state of a solid, that occur at slightly higher temperatures.

Strong Interactions Need Not Apply

A new kind of magnetic order has been observed in barium-cobalt iron arsenide high-temperature superconductors by researchers with expertise in growing large single crystals, conducting x-ray and neutron measurements, and calculating electronic structures. Traditional antiferromagnetic order observed, for example, in the copper oxide high-temperature superconductors is driven by strong electron-electron interactions that can result in insulating behavior.

Harvesting Sunlight with Tadpoles and Drumsticks

Scientists have discovered a method to fine-tune the shapes of nanorod photocatalyst particles. These materials accelerate reactions when they are activated by light and their shape affects their behavior. Researchers showed that the photocatalysts, made from tiny amounts of cadmium, sulfur and selenium, will form selectively into shapes that look like either tadpoles or drumsticks depending on the selenium concentration.

Live from the Lab - SPORT Video

Thanks to the innovation of “single particle orientation and rotation tracking” (SPORT), we now can watch the distinctive movements of drug delivering nanoparticles in real time. Nanoparticles have the potential to revolutionize drug delivery.  When these particles interact with cell membranes they move in all sorts of ways.  They spin, they tumble, they move along and through the membrane.  At least that’s what we think.  But what’s really going

Under Pressure - A Material's Secrets Revealed

Researchers have used pressure as a tool to study the magnetic behavior of a challenging series of materials, RVSb3, where R is a rare-earth.  This series offers a way to study magnetic ordering in materials with a single, unique rare-earth site and it has been studied primarily as a function of temperature. CeVSb3 is the only compound in the family that orders ferromagnetically, that is with all its unpaired electron spins parallel, at low temperatures.

Seeing Order Emerge out of Chaos

Using computer simulations, researchers are able to watch how a random mixture of gold nanoparticles with two different DNA strands as linkers assemble right on their computer screen. The magic starts with just a fraction of the nanoparticles forming a large cluster like a plate of spaghetti and meatballs. Within this random cluster, small ordered regions form and eventually lock together into a large uniform array of particles held together with DNA strands. Using computer simulations they also predict previously unseen structures.

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