Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Squeezed crystals deliver more volts per jolt

31.01.2008
A discovery by scientists at the Carnegie Institution has opened the door to a new generation of piezoelectric materials that can convert mechanical strain into electricity and vice versa, potentially cutting costs and boosting performance in myriad applications ranging from medical diagnostics to green energy technologies.

High-performance piezoelectric materials used today, such as those in probes for medical ultrasound, are specially grown crystals of mixed composition known as “solid solutions,” making them difficult to study and expensive to manufacture. But in the January 31 Nature a research team* led by Ronald Cohen and Russell Hemley of the Carnegie Institution’s Geophysical Laboratory report that at high pressure pure crystals of lead titanate show the same transitions seen in more complex materials.

Moreover, theory predicts that lead titanate under pressure has the largest piezoelectric response of any material known. This suggests the exciting possibility of low-cost but extremely high-performance piezoelectrics.

“The most useful piezoelectric materials have a critical range of compositions called the morphotopic phase boundary, where the crystal structure changes and the piezoelectric properties are maximal,” says Muhtar Ahart, a co-author of the study. “These are usually complex, engineered, solid solutions. But we showed that a pure compound can display a morphotopic phase boundary under pressure.”

For the study, the researchers placed powdered crystals of lead titanate in a device called a diamond anvil cell, which can generate pressures exceeding those at the center of the Earth. They monitored the changes in crystal structure with pressure using high-energy X-ray beams of the Advanced Photon Source at Argonne National Laboratory in Illinois. Using this data and calculations based on first-principle theoretical computations, the researchers were able to determine the piezoelectric properties of the pure crystals at different pressures.

“It turns out that complex microstructures or compositions are not necessary to obtain strong piezoelectricity,” says Ahart.

The use of piezoelectrics has boomed in recent years and is rapidly expanding. Their ability to convert mechanical energy to electric energy and vice versa has made them invaluable for acoustic transducers for sonar and medical ultrasound, and for tiny, high-precision pumps and motors for medical and other applications. High-performance piezoelectrics have also opened up new possibilities for “energy harvesting,” using ambient motion and vibration to generate electricity where batteries or other power sources are impractical or unavailable.

“This is a field in which theory, experiment, and material development work side-by-side,” says Ronald Cohen, a staff scientist at the Carnegie Institution and a co-author of the study. “Delineating the underlying physics of piezoelectric materials will make it easier to develop new materials and improve existing ones. We’re now poised on the edge of hugely expanded applications of these technologies.”

Muhtar Ahart | EurekAlert!
Further information:
http://www.CIW.edu

More articles from Power and Electrical Engineering:

nachricht Stanford researchers develop a new type of soft, growing robot
21.07.2017 | Stanford University

nachricht Team develops fast, cheap method to make supercapacitor electrodes
18.07.2017 | University of Washington

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>