Featured Research

from universities, journals, and other organizations

Recipe for oxide interface perfection opens path to novel materials

Date:
November 16, 2012
Source:
Oak Ridge National Laboratory
Summary:
By tweaking the formula for growing oxide thin films, researchers have achieved virtual perfection at the interface of two insulator materials.

By tweaking the formula for growing oxide thin films, researchers at the Department of Energy's Oak Ridge National Laboratory achieved virtual perfection at the interface of two insulator materials.

This finding, published in the journal Advanced Materials, could have significant ramifications for creation of novel materials with applications in energy and information technologies, leading to more efficient solar cells, batteries, solid oxide fuel cells, faster transistors and more powerful capacitors.

The research team, led by ORNL's Ho Nyung Lee, demonstrated that a single unit cell layer of lanthanum aluminate grown on a strontium titanate substrate is sufficient to stabilize a chemically and atomically sharp interface. A unit cell is the smallest group of atoms that possess the properties of a crystalline material.

"This means that we can now create new properties by precisely conditioning the boundary in the process of stacking different oxides on top of each other," said Lee, a member of the Materials Science and Technology Division.

What's especially noteworthy is that a layer even one unit cell thick could serve as a buffer and dramatically improve the interface quality.

For this research, Lee and colleagues used pulsed laser deposition to deposit lanthanum aluminate thin films on strontium titanate substrates. They were able to demonstrate that a mundane variable such as the oxygen pressure during deposition of lanthanum aluminate is the key factor for achieving atomically sharp interfaces and changing the interface properties on a single unit cell level. Importantly, this finding is not limited to fine-tuning this particular interface, but also applies to a broad range of oxide heterostructures in a class of minerals known as perovskites.

The discovery of electrical properties in oxides -- ordinarily insulators -- has generated excitement and potentially creates the possibility that oxide electronics could become an alternative to the current semiconductor technology based on silicon.

Making this finding possible was Argonne National Laboratory's Advanced Photon Source and the extreme brightness of synchrotrons that allowed scientists to study the structure and composition at the interface.

"The sophisticated surface X-ray diffraction methods available at the Advanced Photon Source were key to zeroing in on the origin of the interface behavior," said co-author and colleague Gyula Eres.

While previous research with lanthanum aluminate thin film growth used low oxygen pressures, Lee and colleagues systematically explored the effects of oxygen pressure in a wide range. They determined that a shielding layer of lanthanum aluminate grown at high oxygen pressure followed by continued growth at a lower pressure resulted in a highly ordered atomically and chemically sharp -- essentially defect-free -- interface.


Story Source:

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


Journal Reference:

  1. Woo Seok Choi, Christopher M. Rouleau, Sung Seok A. Seo, Zhenlin Luo, Hua Zhou, Timothy T. Fister, Jeffrey A. Eastman, Paul H. Fuoss, Dillon D. Fong, Jonathan Z. Tischler, Gyula Eres, Matthew F. Chisholm, Ho Nyung Lee. Atomic Layer Engineering of Perovskite Oxides for Chemically Sharp Heterointerfaces. Advanced Materials, 2012; DOI: 10.1002/adma.201202691

Cite This Page:

Oak Ridge National Laboratory. "Recipe for oxide interface perfection opens path to novel materials." ScienceDaily. ScienceDaily, 16 November 2012. <www.sciencedaily.com/releases/2012/11/121116124347.htm>.
Oak Ridge National Laboratory. (2012, November 16). Recipe for oxide interface perfection opens path to novel materials. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2012/11/121116124347.htm
Oak Ridge National Laboratory. "Recipe for oxide interface perfection opens path to novel materials." ScienceDaily. www.sciencedaily.com/releases/2012/11/121116124347.htm (accessed April 19, 2014).

Share This



More Matter & Energy News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
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