Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Molecule Changes Magnetism and Conductance

05.07.2012
By Electricity, Researchers Switch the Magnetic State and Electric Resistance of a Single Molecule on and off/Blueprint for Novel, Compact Storage Media

One bit of digital information stored on a hard disk currently consists of about 3 million magnetic atoms. Researchers from Karlsruhe, Strasbourg, and Japan have now developed a mag-netic memory with one bit per molecule.


Using a scanning tunneling microscope tip, defined electricity pulses were applied to the molecule, which switches between different magnetic states. (photo: CFN/KIT)

By an electric pulse, the metal-organic molecule can be switched reliably between a conductive, magnetic state and a low-conductive, non-magnetic state. This novel correlation for molecules is now reported in the Nature Communications journal. (doi: 10.1038/ncomms1940)

“The superparamagnetic effect prevents smaller bit sizes from being reached in a hard disk,“ explains Toshio Miyamachi, first author of the study and researcher at the Center for Functional Nanostructures (CFN) of Karlsruhe Institute of Technology (KIT). This super-paramagnetic effect implies that magnetic memory crystals are in-creasingly susceptible to thermal switching with decreasing size. Consequently, information may soon be lost. “We chose another approach and placed a single magnetic iron atom in the center of an organic molecule consisting of 51 atoms. The organic shell protects the information stored in the central atom.” Apart from the ultimate density of one bit per molecule, this type of memory based on so-called spin crossover molecules also has the advantage of the writ-ing process being reliable and purely electric.

“Using a scanning tunneling microscope, we applied defined elec-tricity pulses to the nanometer-sized molecule,” adds Wulf Wulfhe-kel, head of the research group at KIT’s Physikalisches Institut. “This reproducibly changes not only the magnetic state of the iron, but also the electric properties of the molecule.” Hence, the two magnet-ic configurations lead to varying conductances, such that the mag-netic state of the molecule can be determined easily by a simple resistance measurement.

The present study reports the fundamentals and shows the principle feasibility and advantages of memories consisting of spin crossover molecules. “These memristive and spintronic properties combined in a molecule will open up a new field of research,” the researchers are convinced. Memristors are memories that store information in the form of resistance variations. Spintronics uses the magnetic spin of individual particles for information processing.

Work was carried out at the laboratories of the Center for Functional Nanostructures (CFN) of KIT, the Institut de Physique et Chimie des Matériaux (IPCMS) in Strasbourg, the SOLEIL synchrotron in Paris, and the Chiba University, Japan.

The Publication
T. Miyamachi, M. Gruber, V. Davesne, M. Bowen, S. Boukari, L. Joly, F. Scheurer, G. Rogez, T.K. Yamada, P. Ohresser, E. Beaure-paire, W. Wulfhekel, Robust spin crossover and memristance across a single molecule. Nat. Commun. , doi: 10.1038/ncomms1940

Karlsruhe Institute of Technology (KIT) is a public corporation according to the legislation of the state of Baden-Württemberg. It fulfills the mission of a university and the mission of a national research center of the Helmholtz Association. KIT focuses on a knowledge triangle that links the tasks of research, teaching, and innovation.

kes, 03.07.2012

For further information, please contact:

Kosta Schinarakis
PKM, Themenscout
Tel.: +49 721 608-41956
Fax: +49 721 608-43568
E-Mail:schinarakis@kit.edu

Monika Landgraf | EurekAlert!
Further information:
http://www.kit.edu

More articles from Power and Electrical Engineering:

nachricht The role of Sodium for the Enhancement of Solar Cells
17.07.2018 | Max-Planck-Institut für Eisenforschung GmbH

nachricht Behavior-influencing policies are critical for mass market success of low carbon vehicles
17.07.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>