Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

CCNY, Lehman experts find ’magnetic flames’ in molecular magnets exhibit properties akin to fire

23.08.2005


In a groundbreaking experiment, researchers from The City College of New York (CCNY) and Lehman College have measured the speed of magnetic avalanches and discovered that the process is analogous to the flame front of a flammable substance. The discovery of a “magnetic flame” could make it easier for engineers to study the dynamics of fire.



Magnetic avalanches occur when the polarity of a molecular nanomagnet is changed suddenly and sufficient energy is released to cause a chain reaction that changes the polarity of the other molecular nanomagnets in a crystal.

Yoko Suzuki, a graduate student at The City College, devised an experiment to measure the progress of a molecular avalanche through a crystal of Mn12 (manganese) acetate using an array of tiny micrometer sized Hall sensors placed underneath the specimen. Ms. Suzuki observed that the avalanche began at one end of the crystal and propagated at speeds of a few meters per second in the form of a “flame” front that released magnetic energy into the crystal.


“Molecular nanomagnets are the first-known magnetic materials in which the magnetic energy density is sufficient to ignite a ‘magnetic flame,’” said Dr. Myriam P. Sarachik, Distinguished Professor of Physics at CCNY and Ms. Suzuki’s mentor. “This could open a potentially important new road for investigating the dynamics of fire in flammable substances because, unlike chemical burning, magnetic burning is non-destructive, reversible and more readily controlled.”

The investigation into the propagation of magnetic avalanches grew out of a theory suggested by Eugene Chudnovsky and Dmitry Garanin. Dr. Chudnovsky, Distinguished Professor of Physics at Lehman College, collaborated with Ms. Suzuki and Professor Sarachik in the present work.

Chudnovsky and Garanin had theorized that under the right circumstances a magnetic system could be made to emit laser type radiation. They suggested that a magnetic avalanche might initiate such laser action. Measuring the speed of the avalanche would aid in the examination of the theory.

When experimentalists at CCNY discovered that the avalanche propagates at a constant speed of a few meters per second, Professor Chudnovsky proposed that the effect is, in fact, “magnetic burning”. Comparison between theory and experiment confirmed his conjecture.

A paper reporting the discovery of “magnetic burning” by Ms. Suzuki, Professors Sarachik and Chudnovsky and coauthors has been accepted for publication in Physical Review Letters. In addition to CCNY and Lehman College, scientists from the Weizmann Institute in Israel and the University of Florida participated in the project, providing the Hall sensors and crystals, respectively.

Jay Mwamba | EurekAlert!
Further information:
http://www.ccny.cuny.edu

More articles from Physics and Astronomy:

nachricht Individualized fiber components for the world market
23.06.2017 | Laser Zentrum Hannover e.V.

nachricht Innovative LED High Power Light Source for UV
22.06.2017 | Omicron - Laserage Laserprodukte GmbH

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>