Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Spintronic Materials Show Their First Move

Abstract:
Physicists trace the "hopping" of single electrons in magnetic materials

Spintronic Materials Show Their First Move

Los Angeles, CA | March 22, 2005

How much energy does it take for an electron to hop from atom to atom, and how do the magnetic properties of the material influence the rate or ease of hopping? Answers to those questions could help explain why some materials, like those used in a computer hard drive, become conductors only in a magnetic field while they are very strong insulators otherwise. They might also help scientists learn how to use the electron's "spin" (a property analogous to the spinning of a child's toy top), as well as its charge, to carry information in a new field known as spintronics. Stéphane Grenier, a postdoctoral fellow studying electronic excitations, or "electron hopping," at the U.S. Department of Energy's Brookhaven National Laboratory, will describe the techniques he uses and the properties of these materials at the March 2005 meeting of the American Physical Society in Los Angeles, California. His talk will take place on Monday, March 21, at 2:30 p.m. in room 151 of the Los Angeles Convention Center.

"We are looking at something very local, electrons hopping between a pair of atoms, to help us understand important macroscopic effects," Grenier says. "This information could help predict which materials might have the properties needed for particular applications -- say, increasing the storage capacity of computer hard drives -- and direct the fabrication of new materials in which these properties are optimized."

To determine the energy needed by an electron to hop from one atom to another atom, Grenier used a technique called inelastic x-ray scattering at the Advanced Photon Source at Argonne National Laboratory. He shines x-ray light onto the sample and measures the tiny difference in energy between the incoming and outgoing photons. This difference is the amount of energy needed to move the electrons.

He used this technique to study materials with different magnetic "lattices" -- ferromagnetic and antiferromagnetic. In ferromagnetic materials, the atoms' magnetic moments (that is, their spins) are all aligned in the same direction. In antiferromagnetic materials, the magnetic moments of the adjacent atoms point in opposite directions.

"When the magnetic moments are aligned, the electron hopping is increased between particular atoms. That is, more electrons make the jump to their neighbors, and it takes less energy to move them," Grenier says. "While this has been known for a while, we have shown the direction in which the electrons move and exactly what price they 'pay,' in terms of energy, to move, and the influence the magnetic lattice of the material has on this hopping."

The electrons want to align their own magnetic moments, or spins, with that of the atoms in the lattice, he explains. "They will do so only if all the atoms' magnetic moments are aligned -- that is when the 'fare' for hopping has its lowest price," he said.

Electrons moving with their spins aligned in the same direction make a current of spins, which could be used, somewhat like currents of electrical charge are now used, to pass or transform information in future electronic components made of tailored magnetic lattices -- a future generation of circuits based on the science of "spintronics," which is also carried out at Brookhaven Lab.

Grenier's studies, along with theoretical analysis of the materials, may also help scientists understand why some materials possess properties such as superconductivity and "colossal magnetoresistance," the ability of some strong insulators to become good conductors when induced by a magnetic field.

Studies on atomic magnetism have applications for understanding novel materials -- including spintronic materials and superconductors -- that will revolutionize the electronic and energy industries. Such studies using x-rays can only be performed in the U.S. at x-ray synchrotron radiation facilities built and managed by the U.S. Department of Energy's Office of Science.

This research was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science.

####


One of the ten national laboratories overseen and funded primarily by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization. Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more: www.bnl.gov/newsroom



Contact:
Karen McNulty Walsh
631 344-8350
kmcnulty@bnl.gov

Mona S. Rowe
631 344-5056
mrowe@bnl.gov

Copyright © BNL

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Possible Futures

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014

Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014

Spintronics

Graphene and Amaranthus Superparamagnets: Breakthrough nanoparticles discovery of Indian researcher September 23rd, 2014

IEEE International Electron Devices Meeting To Celebrate 60th Anniversary as The Leading Technical Conference for Advanced Semiconductor Devices September 18th, 2014

A new, tunable device for spintronics: An international team of scientists including physicist Jairo Sinova from the University of Mainz realises a tunable spin-charge converter made of GaAs August 29th, 2014

Molecular engineers record an electron's quantum behavior August 14th, 2014

Announcements

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Could I squeeze by you? Ames Laboratory scientists model molecular movement within narrow channels of mesoporous nanoparticles October 21st, 2014

Detecting Cancer Earlier is Goal of Rutgers-Developed Medical Imaging Technology: Rare earth nanocrystals and infrared light can reveal small cancerous tumors and cardiovascular lesions October 21st, 2014

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE