Featured Research

from universities, journals, and other organizations

A glassy look for manganites: Scientists observe glass-like behavior in electron-spins of PCMO crystals

Date:
April 28, 2014
Source:
DOE/Lawrence Berkeley National Laboratory
Summary:
Researchers have discovered a glass-like re-ordering of electron-spin states as manganite crystals recovered from a photo-excited conductor state back to an insulator state. The discovery holds promise for future ultrafast electronic switching and memory devices.

Ultrafast pulses of x-rays from Berkeley Lab’s Advanced Light Source revealed a glass-like re-ordering of electron-spin states in PCMO crystals as samples recovered from a photo-excited conductor state back to the insulator state. In this schematic, circles and lobes show manganese sites and orbitals with pink and blue colors representing opposite spin orientations.
Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory

Manganites -- compounds of manganese oxides -- show great promise as "go-to" materials for future electronic devices because of their ability to instantly switch from an electrical insulator to a conductor under a wide variety of external stimuli, including magnetic fields, photo-excitations and vibrational excitations. This ultrafast switching arises from the many different ways in which the electrons and electron-spins in a manganite may organize or re-organize in response to such external stimuli. Understanding the physics behind these responses is crucial for the future development of manganites.

In a recent study of praseodymium calcium manganite (PCMO) crystals, a model manganite system, researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) discovered that under photo-stimulation the insulator/conductor switching, which depends primarily on charge-ordering, may be ultra-fast, but the re-ordering of electron-spin, upon which magnetic properties depend, is not. In fact, the re-ordering of spin in these materials actually exhibits a glass-like state, in which the restoration of crystalline order is substantially delayed.

"The electron-spins get trapped in a frustrated, disordered state, like cars trying to merge without road signs or lane markers, and can take multiple seconds, a comparatively very long time, to sort themselves out," says Robert Schoenlein of Berkeley Lab's Materials Sciences Division, one of the leaders of this study. "This separation of charge-ordering behavior from spin-ordering behavior may point the way to new approaches to manipulating spin effects for applications in switching and memory devices."

Working at beamline 6.0.2 of Berkeley Lab's Advanced Light Source (ALS), Schoenlein and a team that included Shuyun Zhou and Yi-De Chuang probed spin-ordering in PCMO crystals using a technique called time-resolved resonant soft x-ray scattering spectroscopy (TR-RSXS). In this technique, they pelted PCMO samples with 70 picosecond (trillionths of a second) pulses of x-rays to capture a series of snapshots that revealed how electron-spin ordering is re-established as the samples recover from a photo-excited conductor state back to the insulator state.

"We found that the glass-like behavior of the electron-spins arise from the metastable state created by photo-excitation, a state characterized by spin disordered metallic droplets within the larger charge- and spin-ordered insulating domains," says ALS staff scientist Chuang. "Comparison with time-resolved resistivity measurements suggests that the collapse of spin ordering is correlated with the insulator-to-metal transition, but the recovery of the insulating phase does not depend on the re-establishment of the spin ordering."

Adds Zhou, "Our work provides a new perspective for revealing the fascinating physics hidden in the recovery dynamics of electronic ordering in correlated electron materials after transient photo-excitation, a prominent method for ultrafast manipulation of material properties. Since other transition metal oxides that exhibit intriguing emergent phenomena, such as the high-temperature superconducting cuprates, also have rich competing phases involving dynamic electronic orderings, we should be able to extend similar TR-RSXS studies to those systems as well."

A paper reporting this research has been published in the journal Scientific Reports. The paper is entitled "Glass-like recovery of antiferromagnetic spin ordering in a photo-excited manganite Pr0.7Ca0.3MnO3." Schoenlein, Chuang and Zhou are the corresponding authors.


Story Source:

The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Y. Zhou, M. C. Langner, Y. Zhu, Y.-D. Chuang, M. Rini, T. E. Glover, M. P. Hertlein, A. G. Cruz Gonzalez, N. Tahir, Y. Tomioka, Y. Tokura, Z. Hussain, R. W. Schoenlein. Glass-like recovery of antiferromagnetic spin ordering in a photo-excited manganite Pr0.7Ca0.3MnO3. Scientific Reports, 2014; 4 DOI: 10.1038/srep04050

Cite This Page:

DOE/Lawrence Berkeley National Laboratory. "A glassy look for manganites: Scientists observe glass-like behavior in electron-spins of PCMO crystals." ScienceDaily. ScienceDaily, 28 April 2014. <www.sciencedaily.com/releases/2014/04/140428143313.htm>.
DOE/Lawrence Berkeley National Laboratory. (2014, April 28). A glassy look for manganites: Scientists observe glass-like behavior in electron-spins of PCMO crystals. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2014/04/140428143313.htm
DOE/Lawrence Berkeley National Laboratory. "A glassy look for manganites: Scientists observe glass-like behavior in electron-spins of PCMO crystals." ScienceDaily. www.sciencedaily.com/releases/2014/04/140428143313.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Shipping Crates Get New 'lease' On Life

Shipping Crates Get New 'lease' On Life

Reuters - Business Video Online (July 25, 2014) Shipping containers have been piling up as America imports more than it exports. Some university students in Washington D.C. are set to get a first-hand lesson in recycling. Their housing is being built using refashioned shipping containers. Lily Jamali reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
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:
from the past week

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