Featured Research

from universities, journals, and other organizations

Discovery of new colossal magnetoresistance mechanism

Date:
August 29, 2012
Source:
National Institute for Materials Science
Summary:
A research group including the NIMS Superconducting Properties Unit and others, in joint work with the University of Fukui, discovered a new material, NaCr2O4, which was developed by ultra-high pressure synthesis and displays a novel type of colossal magnetoresistance effect.

A research group* has discovered a new material, NaCr2O4, which displays a novel type of colossal magnetoresistance effect. The new material was developed by ultra-high pressure synthesis.

Materials in which electrical resistance changes by an order of magnitude when a magnetic field is applied are called colossal magnetoresistance (CMR) materials. Virtually all known CMR materials are oxides of manganese, and their CMR mechanism also depends on a special ferromagnetic-metallic phase of manganese ions. However, new CMR mechanisms and material search guidelines which do not rely on manganese oxides have been demanded.

In this research, a new material, NaCr2O4, was developed by ultra-high pressure synthesis, focusing on the following two points:

(1) Calcium ferrite structures have both a 1-dimensional crystal structure and a structure which displays magnetic frustration, and

(2) oxides with tetravalent ions of Cr have a special electronic state.

It was found that a CMR effect occurs in NaCr2O4, which is not a ferromagnetic metal, but rather, is an antiferromagnetic semiconductor. Although the CMR effect appears over a wide temperature range, i.e., the entire temperature range below the magnetic transition temperature, this is a CMR effect with a new mechanism, which has the novel feature of not displaying history effects with respect to temperature or the magnetic field.

This result has important implications for the search for CMR materials, as it is also necessary to consider the antiferromagnetic semiconductors, which had seemed unrelated to the CMR effect until now. The new mechanism proposed as a result of this research has the potential to become a new material search guideline, as the CMR effect can be considered to occur in the diverse structures of various transition metal compounds.

*Dr. Hiroya Sakurai, Senior Researcher, Dr. Taras Kolodiazhnyi, Senior Researcher, and Dr. Yuichi Michiue, Principal Researcher of the Superconducting Properties Unit, National Institute for Materials Science (NIMS, President: Sukekatsu Ushioda), Dr. Eiji Muromachi, Vice President of NIMS, and others, in joint work with Professor Hikomitsu Kikuchi and Mr. Yuichi Tanabe of the University of Fukui.


Story Source:

The above story is based on materials provided by National Institute for Materials Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hiroya Sakurai, Taras Kolodiazhnyi, Yuichi Michiue, Eiji Takayama-Muromachi, Yuichi Tanabe, Hikomitsu Kikuchi. Unconventional Colossal Magnetoresistance in Sodium Chromium Oxide with a Mixed-Valence State. Angewandte Chemie International Edition, 2012; 51 (27): 6653 DOI: 10.1002/anie.201201884

Cite This Page:

National Institute for Materials Science. "Discovery of new colossal magnetoresistance mechanism." ScienceDaily. ScienceDaily, 29 August 2012. <www.sciencedaily.com/releases/2012/08/120829112226.htm>.
National Institute for Materials Science. (2012, August 29). Discovery of new colossal magnetoresistance mechanism. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2012/08/120829112226.htm
National Institute for Materials Science. "Discovery of new colossal magnetoresistance mechanism." ScienceDaily. www.sciencedaily.com/releases/2012/08/120829112226.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Portable Breathalyzer Gets You Home Safely

Portable Breathalyzer Gets You Home Safely

Buzz60 (Oct. 21, 2014) Breeze, a portable breathalyzer, gets you home safely by instantly showing your blood alcohol content, and with one tap, lets you call an Uber, a cab or a friend from your contact list to pick you up. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins