Electric rocket engines known as Hall thrusters, which use a super high-velocity stream of ions to propel a spacecraft in space, have been used successfully onboard many missions for half a century. Erosion of the discharge channels walls, however, has limited their application to the inner solar system. A research team at Caltech's Jet Propulsion Laboratory has found a way to effectively control this erosion by shaping the engine's magnetic field in a way that shields the walls from ion bombardment.
Engineers at the Korea Advanced Institute of Science and Technology (KAIST) and the Korea Railroad Research Institute have designed a wireless technology that can be applied to high capacity transportation systems such as railways, harbor freight, and airport transportation, and logistics. The technology supplies 60 kHz and 180 kW of power remotely to transport vehicles at a stable, constant rate.
Researchers have recently demonstrated magnetic resonance imaging (MRI) on the molecular scale through the use of artificial atoms, diamond nanoparticles doped with nitrogen impurity. Conventional MRI responds to the magnetic fields of atomic nuclei, but this new method improves resolution nearly one million times, allowing scientists to probe very weak magnetic fields such as those generated in some biological molecules and even proteins.
When migrating, sockeye salmon typically swim up to 4,000 miles into the ocean and then, years later, navigate back to the upstream reaches of the rivers in which they were born to spawn their young. Scientists have long wondered how salmon find their way to their home rivers over such epic distances. A new study suggests that salmon find their home rivers by sensing the rivers' unique magnetic signature.
Research by an international team of physicists has produced new methods for controlling magnetic order in a particular class of materials known as "magnetoelectrics", which have their magnetic and electric properties couple to each other. This link offers the possibility of controlling electric behavior with a magnetic signal, or vice versa. Scientists recently demonstrated this ability in europium-titanium oxide.
Researchers in Switzerland have designed tiny vessels that are capable of releasing active agents in the body. These “nanovehicles” are made from a liposome just 100 to 200 nm in diameter. By attaching magnetic iron oxide nanoparticles to the surface, scientists are able to target the vessel, heating it up to release the drug.
Physicists have recently demonstrated that the application of a very strong alternating electric field to thin liquid crystal cells leads to a new distinct nonlinear dynamic effect in the response of the cells. Researchers were able to explain this result through spatio-temporal chaos theory. The finding has implications for the operation of liquid crystal devices because their operation depends on electro-optic switch phenomena.
The Barkhausen Effect is the noise in the magnetic output of a ferromagnet when the magnetizing force applied to it is changed. Almost 100 years after its initial discovery, a team of scientists in Alberta have harnessed this effect as a new kind of high-resolution microscopy for the insides of magnetic materials.
In science, just like in life, sometimes creating the most effective organization depends on being able to handle just a bit of chaos first. Scientists at Argonne National Laboratory have used alternating magnetic fields to control the behavior of "spin vortices" trapped in small dots made from iron and nickel that can be magnetized in two separate ways.
Following up on earlier theoretical predictions, Massachusetts Institute of Technology researchers have now demonstrated experimentally the existence of a fundamentally new kind of magnetic behavior, adding to the two previously known states of magnetism.
Evaporative cooling has long been used to cool atoms, but it has never before been done by molecules—two different atoms bonded together. Achieving a goal considered nearly impossible, JILA physicists have done this, chilling a gas of molecules to very low temperatures by adapting the familiar process by which a hot cup of coffee cools.
A team of scientists has studied magnons in a material that becomes helimagnetic below about 30 K: iron silicide doped with cobalt. They investigated how helimagnons evolve as the temperature increases, destroying the magnetic order, as well as how the magnetic phases are affected by an external magnetic field.
Inductors are essential components of integrated circuits. The sprawling metal spirals store magnetic energy, acting as a buffer against changes in current and modulating frequency. However, because inductance depends on the number of coils, they take up a lot of space. Researchers have recently build a 3D rolled-up inductor with a footprint more than 100 times smaller without sacrificing performance.
Engineers in Texas have adopted the nanoscale fabrication technique of directed self-assembly to increase the surface storage density of hard disk drives. The method, which relies on block copolymers, is able to organize magnetic dots into patterns far finer than existing methods. And it does so without risking the integrity of the magnetic fields.
In a tornado, the individual air particles do not necessarily rotate on their own axis, but the air suction overall creates a powerful rotation. Similar vortex beams are being used in electron microscopy to allow researchers to determine the angular momentum of materials under examination. This ability provides valuable information about a material’s magnetic field. Researchers in Austria have recently produced particularly intense vortex beams.
For the first time, three separately found extreme Earth events have been compared by researchers who now believe they may be linked. About 41,000 years ago, a complete and rapid reversal of the geomagnetic field occurred, lasting for just a few hundred years. Around the same time, a super volcano erupted and major climate changes occurred.
Magnetotactic bacteria are organisms which develop membrane-encapsulated nano-particles known as magnetosomes. Although these microbes were first discovered in 1975, the production of their magnetite crystals is still not fully understood. A researcher in the U.K. is now using computational simulation tools to discover how magnetosomes allow bacteria to orient themselves along the Earth’s magnetic field lines.
Magnetized iron can be demagnetized extremely quickly (just a few hundred femtoseconds) when it is radiated with laser light pulses. Researchers in Europe have used x-ray light to reveal a new cause for this loss of magnetism. They found that electrons can move very quickly between areas with different magnetization and polarization, thereby influencing the demagnetization of the material. The effect could play a decisive role in reducing the size of magnetic memories.
A University of Delaware research team’s exploration of paramagnetic colloids—microscopic particles that are mere hundredths the diameter of a human hair—has produced the possibility that computer chips could one day build themselves in a scalable fashion. By applying a magnetic field to the colloids, the team build organized crystalline lattices from random solids.
An international team of researchers have demonstrated a microscopy method to identify magnetic defects in an array of magnetic nanostructures. The method represents an important step towards identifying, measuring, and correcting the magnetic properties of defective devices in future information storage technologies.
Massachusetts Institute of Technology researchers have developed a new technique for magnetically separating oil and water that could be used to clean up oil spills. They believe that, with their technique, the oil could be recovered for use, offsetting much of the cleanup cost.
A team of researchers at in Japan has demonstrated a new material that promises to eliminate loss in electrical power transmission. Their methodology for solving this classic energy problem is based on a highly exotic type of magnetic semiconductor first theorized less than a decade ago—a magnetic topological insulator.
Scientists at IBM Research and ETH Zurich in Switzerland report that they are the first to synchronize electron spins and image the formation of a persistent spin helix in a semiconductor. Until now, it was unclear whether electron spins could preserve encoded information long enough before rotating. This new work extends spin lifetime 30-fold, to 1.1 nanosec.
Multiferroics are expected to be applied to a new type of memory devices in which dielectric polarization is controlled by a magnetic field and magnetization is controlled by an electric field. However, multiferroic materials that function at room temperature are rare. In a breakthrough toward this goal, a team in Japan and the U.K. have achieved ferroelectric polarization without a magnetic field after discovering that they could swap out atoms and still maintain control of the multiferroic’s dielectric and magnetic properties.
Traditional mechanical couplings and gears require lubrication, generate heat, emit vibrations and sound, suffer from structural wear and require significant maintenance. Correlated Magnetics Research has been tasked with a Small Business Innovation Research grant to design and develop high-torque magnetic couplings to produce quiet, maintenance free, power-transfer linkages for Naval systems and industrial applications.