Chemistry 2011.org
Chemistry2011.org
All About Chemistry... 2011 and beyond

Related Stories

Explanation for strange magnetic behavior at semiconductor interfaces

Aug. 25, 2013 — They're not exactly the peanut butter and jelly of semiconductors, but when you put them together, something magical happens.

Alone, neither lanthanum aluminate nor strontium titanate exhibit any particularly notable properties. But when they are layered together, they become not only conductive, but also magnetic.

In the current online edition of Nature Physics, researchers at The Ohio State University report the first-ever theoretical explanation to be offered for this phenomenon since it was discovered in 2004.

Understanding how these two semiconductors interact at their interface could someday lead to a different kind of material -- one that provides a single platform for computation and data storage, said Mohit Randeria, co-author of the paper and professor of physics at Ohio State.

"The whole question is, how can you take two materials which do not conduct electricity and do not have magnetic properties, make a sandwich out of them and -- lo and behold -- at the interface tween them, charge begins to flow and interesting magnetic effects happen?" he said.

"It's like taking two pieces of bread and putting them together and having the sandwich filling magically appear."

By making calculations and modeling the basic physical properties of both materials, Randeria's team has hit upon an explanation for the behavior that seems ironic: the interface between two non-magnetic materials exhibits magnetism.

The team showed how the elemental units of magnetism, called "local moments," are formed at the interface of the two materials. They then showed how these moments interact with the conducting electrons to give rise to a magnetic state in which the moments are arranged in an unusual spiral pattern.

If the physicists' explanation is correct, then perhaps someday, electronic devices could be constructed that exploit the interface between two oxides. Theoretically, such devices would combine the computational abilities of a silicon chip with the magnetic data storage abilities of permanent magnets like iron.

"If you had conduction and magnetism available in the same platform, it could be possible to integrate computer memory with data processing. Maybe different kinds of computation would be possible," Randeria said.

But those applications are a long way off. Right now, the physicists hope that their theoretical explanation for the strange magnetic behavior will enable other researchers to perform experiments and confirm it.

Randeria's coauthors included Ohio State postdoctoral researcher Sumilan Banerjee and former doctoral student Onur Erten, who graduated this summer and is about to begin a postdoctoral fellowship at Rutgers, The State University of New Jersey.

This research was sponsored by the U.S. Department of Energy, the National Science Foundation (NSF), and Ohio State's Center for Emergent Materials, one of a network of Materials Research Science and Engineering Centers funded by NSF.

Share this story with your friends!

Social Networking

Please recommend us on Facebook, Twitter and more:

Other social media tools

Global Partners
Feedback

Tell us what you think of Chemistry 2011 -- we welcome both positive and negative comments. Have any problems using the site? Questions?

About us

Chemistry2011 is an informational resource for students, educators and the self-taught in the field of chemistry. We offer resources such as course materials, chemistry department listings, activities, events, projects and more along with current news releases.

Events & Activities

Are you interested in listing an event or sharing an activity or idea? Perhaps you are coordinating an event and are in need of additional resources? Within our site you will find a variety of activities and projects your peers have previously submitted or which have been freely shared through creative commons licenses. Here are some highlights: Featured Idea 1, Featured Idea 2.

About you

Ready to get involved? The first step is to sign up by following the link: Join Here. Also don’t forget to fill out your profile including any professional designations.

Global Partners