Featured Research

from universities, journals, and other organizations

Researchers Discover The Peak Of Efficiency For Systems Used In Ultrasound, Sonar

Date:
September 13, 2001
Source:
University Of Arkansas
Summary:
University of Arkansas researchers have found a novel physical effect of systems used in ultrasound and sonar that is ten times stronger than current methods used in these techniques. This large ratio of physical change to electric effect may be used one day to create more sensitive and more portable sonar devices and medical ultrasound equipment.

FAYETTEVILLE, Ark. -- University of Arkansas researchers have found a novel physical effect of systems used in ultrasound and sonar that is ten times stronger than current methods used in these techniques. This large ratio of physical change to electric effect may be used one day to create more sensitive and more portable sonar devices and medical ultrasound equipment.

Graduate student Aaron George, visiting scientist Jorge Ininguez, now at Rutgers University, and assistant professor of physics Laurent Bellaiche report their findings in the September 6 issue of the journal Nature.

"This finding means we can drastically improve the response of devices," which will help advance sonar and ultrasound used in both the military and medical fields, Bellaiche said.

The scientists used computer models to study the properties of piezoelectric compounds, crystals that change shape when encountering an electric field, or create an electric field when they change shape. Piezoelectric compounds are found in ultrasound devices, which are used by doctors to noninvasively examine fetuses and internal organs, and in sonar, used by submarine personnel for underwater navigation and detection.

Some piezoelectric systems form crystals with two different types of atoms distributed throughout. Bellaiche and his colleagues sought to find out if they could guide the atomic arrangement of such crystals by placing the two different atoms in layers rather than randomly. They wanted to see what the piezoelectric and other responses of such crystals might be.

They selected a structure with the amount of Scandium and Niobium (Sc and Nb) atoms inside each layer as the variables, and created a model that could calculate the amounts of the two atoms, which have different atomic numbers and therefore different charges.

Scandium has a charge of +3, Niobium a charge of +5. By changing the ratio of the atoms inside each layer, the researchers create strong internal electric fields in different directions, causing the crystal to change structural phases.

Some ratios created an electrical polarization in one direction, creating a rhombohedral phase, while others switched the direction of polarization and created another phase, called an orthorhombic phase, an effect not seen before. Furthermore, in between the two polarized phases, the researchers discovered a large piezoelectric response that is ten times larger than responses currently used commercially.

"It's a new fundamental structural property," Bellaiche said.

The large piezoelectric response represents the process of changing shape, and it is at this point that a small electrical pulse can produce the largest change.

The researchers performed most of their computations at a temperature of 20 K, but the same result can be found at any temperature.

"At any range you can have a structure that will give you a huge response," Bellaiche said. Changing the temperature will just mean the large effect will take place with a different ratio of the two atoms.

The atomic structures Bellaiche and his colleagues have modeled can be grown using molecular beam epitaxy, a technique available at the University of Arkansas and some other research institutions and companies.


Story Source:

The above story is based on materials provided by University Of Arkansas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Arkansas. "Researchers Discover The Peak Of Efficiency For Systems Used In Ultrasound, Sonar." ScienceDaily. ScienceDaily, 13 September 2001. <www.sciencedaily.com/releases/2001/09/010913081020.htm>.
University Of Arkansas. (2001, September 13). Researchers Discover The Peak Of Efficiency For Systems Used In Ultrasound, Sonar. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2001/09/010913081020.htm
University Of Arkansas. "Researchers Discover The Peak Of Efficiency For Systems Used In Ultrasound, Sonar." ScienceDaily. www.sciencedaily.com/releases/2001/09/010913081020.htm (accessed September 22, 2014).

Share This



More Matter & Energy News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thousands March in NYC Over Climate Change

Thousands March in NYC Over Climate Change

AP (Sep. 21, 2014) — Accompanied by drumbeats, wearing costumes and carrying signs, thousands of demonstrators filled the streets of Manhattan and other cities around the world on Sunday to urge policy makers to take action on climate change. (Sept. 21) Video provided by AP
Powered by NewsLook.com
What This MIT Sensor Could Mean For The Future Of Robotics

What This MIT Sensor Could Mean For The Future Of Robotics

Newsy (Sep. 20, 2014) — MIT researchers developed a light-based sensor that gives robots 100 times the sensitivity of a human finger, allowing for "unprecedented dexterity." Video provided by Newsy
Powered by NewsLook.com
MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) — The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) — Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
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