Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Colossal Conducting Variation at the Nanoscale: Colossal magnetoresistance phenomenon occurs when nanoclusters form at specific temperatures

Abstract:
Researchers at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and the Universidad San Francisco de Quito in Ecuador have found that, at just the right temperatures, nanoclusters form and improve the flow of electrical current through certain oxide materials. This work could be used in a number of industrial applications including spintronics, which exploit electrical and magnetic properties for use in solid-state electronics. The researchers' findings will appear in the Proceedings of the National Academy of Sciences during the week of December 12, 2011.

Colossal Conducting Variation at the Nanoscale: Colossal magnetoresistance phenomenon occurs when nanoclusters form at specific temperatures

Upton, NY | Posted on December 12th, 2011

The unusually large variation in resistance to the flow of electricity in the presence of a magnetic field observed in some oxide materials is a phenomenon known as colossal magnetoresistance. The oxides involved in this research have a specific arrangement among the atoms that make up the material. The scientists found that, at particular temperatures in a magnetic field, nanoclusters about 10 atoms in size formed in these materials. These nanoclusters had electronic properties different from the material's whole and were essential to the emergence of colossal magnetoresistance.

"Until now, scientists could only speculate that nanoclusters play a critical role in colossal magnetoresistance. Our work pinpointing the nanoclusters with improved conductivity is a big step in understanding this phenomenon and the fundamental laws of materials," said Brookhaven physicist Jing Tao, lead author on the paper.

"As we cooled samples from room temperature to about 250 Kelvin (-23 degrees Celsius), we found that colossal magnetoresistance emerged as nanoclusters formed and became most dense," Jing explained. "We saw the nanoclusters form and connect a path in the crystal, and the whole material became conducting."

These nanoclusters were thought to only act as insulators with different magnetic properties, Jing added. This work shows that these properties are temperature dependent. In the presence of a magnetic field and at the proper temperature, the nanoclusters become conductive and ferromagnetic to allow colossal magnetoresistance to occur.

For this research, scientists at the Universidad San Francisco de Quito in Ecuador grew crystals of manganite - manganese oxide doped with varying quantities of calcium and the rare-earth metal lanthanum. Scientists at Brookhaven then bombarded the crystals with beams of high-powered, negatively charged electrons using the Lab's Transmission Electron Microscope to study their properties. As the electrons passed through the crystal, the scientists analyzed their paths and energy levels to determine properties such as structure and magnetism, as well as the nanoclusters' role in the emergence of colossal magnetoresistance.

"Thanks to the unique instruments at Brookhaven, we also found a new level of complexity in the material with colossal magnetoresistance," said Tao. "We know now that these nanoclusters form and enable colossal magnetoresistance at certain temperatures, but we don't yet know why or how they interact with the material as a whole.

"In the future when we learn more about the nanoclusters - for example, the details of their structure and whether they are charged - we can begin to improve the electrical performance of these materials."

The work completed at Brookhaven Lab was supported by DOE's Office of Science. Authors of the paper include Tao, Qing Jie, Marvin A. Schofield, LiJun Wu, Qiang Li, and Electron Microscopy and Nanostructure Group Leader Yimei Zhu, from Brookhaven Lab, as well as Dario Niebieskikwiat from the Universidad San Francisco de Quito. Additional scanning experiments were conducted at the University of Illinois.

Writer: Joe Gettler

####

About Brookhaven National Laboratory
One of ten national laboratories overseen and primarily funded 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 the Research Foundation of the State University of New York, for and on behalf of Stony Brook University, the largest academic user of Laboratory facilities; and Battelle Memorial Institute, a nonprofit, applied science and technology organization. Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more (www.bnl.gov/newsroom) or follow Brookhaven Lab on Twitter (twitter.com/BrookhavenLab).

For more information, please click here

Contacts:
Karen McNulty Walsh
631 344-8350

or
Peter A. Genzer
631 344-3174

Copyright © Brookhaven National Laboratory

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

News and information

Forces of nature: Interview with microscopy innovators Gerd Binnig and Christoph Gerber August 26th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Laboratories

A new way to display the 3-D structure of molecules: Metal-organic frameworks provide a new platform for solving the structure of hard-to-study samples August 21st, 2016

Scientists uncover origin of high-temperature superconductivity in copper-oxide compound: Analysis of thousands of samples reveals that the compound becomes superconducting at an unusually high temperature because local electron pairs form a 'superfluid' that flows without resist August 19th, 2016

Let's roll: Material for polymer solar cells may lend itself to large-area processing: 'Sweet spot' for mass-producing polymer solar cells may be far larger than dictated by the conventional wisdom August 12th, 2016

NREL technique leads to improved perovskite solar cells August 11th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

New approach to determining how atoms are arranged in materials August 25th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Spintronics

Swapping substrates improves edges of graphene nanoribbons: Using inert boron nitride instead of silica creates precise zigzag edges in monolayer graphene August 2nd, 2016

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

A mini-antenna for the data processing of tomorrow: Nature Nanotechnology: Short-wavelength spin waves generated directly for the first time July 20th, 2016

A new spin on reality July 15th, 2016

Chip Technology

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

Silicon nanoparticles trained to juggle light: Research findings prove the capabilities of silicon nanoparticles for flexible data processing in optical communication systems August 25th, 2016

AIM Photonics Announces Release of Process Design Kit (PDK) for Integrated Silicon Photonics Design August 25th, 2016

Discoveries

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Announcements

Forces of nature: Interview with microscopy innovators Gerd Binnig and Christoph Gerber August 26th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

Nanofiber scaffolds demonstrate new features in the behavior of stem and cancer cells August 25th, 2016

Research partnerships

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

New theory could lead to new generation of energy friendly optoelectronics: Researchers at Queen's University Belfast and ETH Zurich, Switzerland, have created a new theoretical framework which could help physicists and device engineers design better optoelectronics August 23rd, 2016

A new way to display the 3-D structure of molecules: Metal-organic frameworks provide a new platform for solving the structure of hard-to-study samples August 21st, 2016

Researchers watch catalysts at work August 19th, 2016

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







Car Brands
Buy website traffic