The innovative process allows them to create room-temperature ferromagnetic materials that are stable for long periods more effectively and with fewer steps than more complicated existing methods. The approach is outlined by UMass Amherst polymer scientist Gregory Tew and colleagues in the Sept. 27 issue of Nature Communications.
Tew explains that his group’s signature improvement is a one-step method to generate ordered magnetic materials based on cobalt nanostructures by encoding a block copolymer with the appropriate chemical information to self-organize into nanoscopic domains. Block copolymers are made up of two or more single-polymer subunits linked by covalent chemical bonds.
The new process delivers magnetic properties to materials upon heating the sample once to a relatively low temperature, about 390 degrees (200 degrees Celsius), which transforms them into room-temperature, fully magnetic materials. Most previous processes required either much higher temperatures or more process steps to achieve the same result, which increases costs, Tew says.
He adds, “The small cobalt particles should not be magnetic at room temperature because they are too small. However, the block copolymer’s nanostructure confines them locally which apparently induces stronger magnetic interactions among the particles, yielding room-temperature ferromagnetic materials that have many practical applications.”
“Until now, it has not been possible to produce ordered, magnetic materials via block copolymers in a simple process,” Tew says. “Current methods require multiple steps just to generate the ordered magnetic materials. They also have limited effectiveness because they may not retain the fidelity of the ordered block copolymer, they can’t confine the magnetic materials to one domain of the block copolymer, or they just don’t produce strongly magnetic materials. Our process answers all these limitations.”
Magnetic materials are used in everything from memory storage devices in our phones and computers to the data strips on debit and credit cards. Tew and colleagues have discovered a way to build block copolymers with the necessary chemical information to self-organize into nanoscopic structures one millionth of a millimeter thin, or about 50,000 times thinner than the average human hair.
Earlier studies have demonstrated that block copolymers can be organized over relatively large areas. What makes the UMass Amherst research group’s results so intriguing, Tew says, is the possible coupling of long-range organization with improved magnetic properties. This could translate into lower-cost development of new memory media, giant magneto-resistive devices and futuristic spintronic devices that might include “instant on” computers or computers that require much less power, he points out.
He adds, “Although work remains to be done before new data storage applications are enabled, for example making the magnets harder, our process is highly tunable and therefore amendable to incorporating different types of metal precursors. This result should be interesting to every scientist in nanotechnology because it shows conclusively that nano-confinement leds to completely new properties, in this case room temperature magnetic materials.”
“Our work highlights the importance of learning how to control a material’s nanostructure. We show that the nanostructure is directly related to an important and practical outcome, that is, the ability to generate room-temperature magnets.”
“Our work highlights the importance of learning how to control a material’s nanostructure. We show that the nanostructure is directly related to an important and practical outcome, that is, the ability to generate room temperature magnets.” As part of this study, the UMass Amherst team also demonstrated that using a block copolymer or nanoscopic material results in a material that is magnetic at room temperature. By contrast, using a homopolymer, or unstructured material, leads only to far less useful non- or partial-magnetic materials.
Gregory N. Tew | Newswise Science News
IceCube experiment finds Earth can block high-energy particles from nuclear reactions
24.11.2017 | Penn State
New proton record: Researchers measure magnetic moment with greatest possible precision
24.11.2017 | Johannes Gutenberg-Universität Mainz
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences