Studies On Electric Polarization Open Potential For Tinier Devices
Researchers from the U.S. Department of Energy's Argonne National Laboratory and Northern Illinois University have shown 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 ability to hold a switchable electric polarization � is stable for thicknesses as small as 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 had found that, as the material became too thin, it quit being a ferroelectric. These new 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.
"The natural ordering of the atoms in their crystal structure cause these materials to be electrically polarized," said researcher Carol Thompson of NIU.
"This means that, in the jargon of the scientists, these ferroelectric materials exhibit rich and complex couplings between their optical, chemical, mechanical, structural and thermal properties. Alterations of the natural structure due to size and surface effects will perhaps destroy their ability to perform as ferroelectrics. However, we will be relying on these materials to behave themselves. Will they? The research suggests that they will behave better than we had any right to expect before."
An increasingly wide range of applications are based on ferroelectric thin films, including sensors, microelectromechanical systems and memory systems.
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 researchers used the powerful X-ray beams from the Advanced Photon Source at Argonne � the nation's most brilliant X-rays � to monitor the electric 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.
The authors are D.D. Fong, G.B. Stephenson, S.K. Streiffer, J.A. Eastman, Orlando Auciello and P.H. Fuoss of Argonne and Carol 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.
Argonne National Laboratory
Advanced Photon Source
Subscribe To SpaceDaily Express
"Lab-On-A-Chip" Could Protect Astronauts And Detect New Life
Huntsville AL (SPX) Jun 02, 2004
Imagine a huge laboratory filled with people and equipment shrinking to fit on a small chip � the size of a dime. Scientists on Earth use labs on chips for medical tests and other research. Marshall Center scientists are customizing these chips for use in space. One day they may be used in devices to detect contaminates, and rovers may use them to identify life on Mars.
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.