Northern Illinois University

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News Release

Contact: Joe King, NIU Office of Public Affairs
(815) 753-4299

Catherine Foster, Argonne National Laboratory
(630) 252-5580

(This release created jointly by NIU and Argonne National Laboratory)

Research helps open door to nanoscale machines

Argonne, Ill. — Researchers from the U.S. Department of Energy’s Argonne National Laboratory and Northern Illinois University have found that very thin materials can still retain an electric polarization, opening the potential for a wide range of tiny devices.

 

The researchers found that the ferroelectric phase – the phase that has the ability to hold a switchable electric polarization – is stable even for thicknesses as small as six atoms. That is the equivalent of 1.2 nanometers, one-billionth of a meter, or a size several hundred thousand times smaller than the period at the end of this sentence. Previous studies found that as the material became too thin, it quit being a ferroelectric. These results, however, suggest that small thicknesses do not pose a fundamental problem to building very small devices based on these materials.

 

The research is published in the June 11 issue of Science magazine.

 

An increasingly wide range of applications are based on ferroelectric thin films, including sensors, microelectromechanical systems, and memories.

 

Studies of ferroelectrics have become more intense in recent years, as devices – and the materials and thin films used to manufacture them – have become smaller, moving to the micro- and even the nano-scale, creating machines and building blocks of electronic devices smaller than the width of a human hair.  The technological potential of these materials depends on maintaining a stable ferroelectric phase as devices continue to be miniaturized.

 

“The better we understand how these materials behave at the nano level, the more accurately we can predict how they will behave under all conditions,” said Carol Thompson, a Northern Illinois University physics professor who is part of the research team. “When we can do that, we can better devise new ways to use these materials in new technologies.”

 

The researchers used the powerful X-ray beams from the Advanced Photon Source at Argonne – the nation’s most brilliant X-rays – to monitor the ferroelectric transition in thin films as they are grown, layer by layer.

 

Argonne is building a new Center for Nanoscale Materials that will provide enhanced capability to fabricate and study novel materials and devices at the nanoscale, such as the work presented here.

 

The authors are D.D. Fong, G.B. Stephenson, S.K. Streiffer, J.A. Eastman, Orlando Auciello and P.H. Fuoss of Argonne and Thompson of NIU. Funding is provided by the Office of Basic Energy Sciences, part of the Department of Energy’s Office of Science, and by the State of Illinois.

 

The nation’s first national laboratory, Argonne National Laboratory conducts basic and applied scientific research across a wide spectrum of disciplines, ranging from high-energy physics to climatology and biotechnology. Argonne has worked with more than 600 companies and numerous federal agencies and other organizations to help advance America's scientific leadership and prepare the nation for the future. The University of Chicago operates Argonne as part of the U.S. Department of Energy’s national laboratory system.

 

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