Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Crystals for efficient refrigeration

The image shows a molecular dynamics simulation of lithium niobate under a time varying electric field, which changes the sign of the polarization. Red is niobium, green is oxygen, and lithium shows a range of colors for different time steps. The niobium and oxygen are shown only for one time step for clarity. The image shows a small part of the actual simulation.

Credit: Maimon Rose and Ronald Cohen Carnegie Institution
The image shows a molecular dynamics simulation of lithium niobate under a time varying electric field, which changes the sign of the polarization. Red is niobium, green is oxygen, and lithium shows a range of colors for different time steps. The niobium and oxygen are shown only for one time step for clarity. The image shows a small part of the actual simulation.

Credit: Maimon Rose and Ronald Cohen Carnegie Institution

Abstract:
Researchers at the Carnegie Institution have discovered a new efficient way to pump heat using crystals. The crystals can pump or extract heat, even on the nanoscale, so they could be used on computer chips to prevent overheating or even meltdown, which is currently a major limit to higher computer speeds. The research is published in the Physical Review Letters.

Crystals for efficient refrigeration

Washington, DC | Posted on November 5th, 2012

Ronald Cohen, staff scientist at Carnegie's Geophysical Laboratory and Maimon Rose, originally a high school intern now at the University of Chicago carried out the research. They performed simulations on ferroelectric crystals—materials that have electrical polarization in the absence of an electric field. The electrical polarization can be reversed by applying an external electrical field. The scientists found that the introduction of an electric field causes a giant temperature change in the material, dubbed the electrocaloric effect, far above a temperature to a so-called paraelectric state.

"The electrocaloric effect pumps heat through changing temperature by way of an applied electric field," explained Cohen. "The effect has been known since the 1930s, but has not been exploited because people were using materials with high transition temperatures. We found that the effect is larger if the ambient temperature is well above the transition temperature, so low transition temperature materials are preferred."

Ferroelectrics become paraelectric—that is, have no polarization under zero electric field above their transition temperature, which is the temperature at which a material changes its state from ferroelectric to paraelectric.

Rose and Cohen used atomic-scale molecular dynamics simulations, where they followed the behavior of atoms in the ferroelectric lithium niobate as functions of temperature and an electrical field. Maimon Rose started this work as a high school summer intern and is now in his second year as an undergraduate in biology at the University of Chicago. He worked on the project during breaks as an intern supported by EFree, DOE Energy Frontier Research Center at the Geophysical Laboratory. Rose remarked, "Lithium niobate had not been studied before like this. We were pretty surprised to see such a huge temperature change."

*The work was supported by the Center for Energy Frontier Research in Extreme Environments (EFree) at the Carnegie Institution's Geophysical Laboratory.

####

About Carnegie Institution
The Carnegie Institution (www.Carnegiescience.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary sciences.

For more information, please click here

Contacts:
Ronald Cohen

202-478-8937

Copyright © Carnegie Institution

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Using light to propel water : With new method, MIT engineers can control and separate fluids on a surface using only visible light April 25th, 2017

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

Russian scientists create new system of concrete building structures: Sientists of Peter the Great Saint-Petersburg Polytechnic University developed a new construction technology April 24th, 2017

Laboratories

NIST physicists show ion pairs perform enhanced 'spooky action' March 30th, 2017

A big leap toward tinier lines: Self-assembly technique could lead to long-awaited, simple method for making smaller microchip patterns March 27th, 2017

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Researchers develop groundbreaking process for creating ultra-selective separation membranes: Discovery could greatly improve energy-efficiency of separation and purification processes in the chemical and petrochemical industries March 15th, 2017

Physics

NIST physicists show ion pairs perform enhanced 'spooky action' March 30th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

Better living through pressure: Functional nanomaterials made easy April 19th, 2017

Chip Technology

'Neuron-reading' nanowires could accelerate development of drugs for neurological diseases April 12th, 2017

Nanometrics to Announce First Quarter Financial Results on May 2, 2017 April 11th, 2017

AIM Photonics Presents Cutting-Edge Integrated Photonics Technology Developments to Packed House at OFC 2017, the Optical Networking and Communication Conference & Exhibition April 11th, 2017

Photonics breakthough paving the way for improved wireless communication systems: The work could bolster the wireless revolution underway with efficiencies several orders of magnitude April 5th, 2017

Discoveries

Using light to propel water : With new method, MIT engineers can control and separate fluids on a surface using only visible light April 25th, 2017

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

Russian scientists create new system of concrete building structures: Sientists of Peter the Great Saint-Petersburg Polytechnic University developed a new construction technology April 24th, 2017

Announcements

Using light to propel water : With new method, MIT engineers can control and separate fluids on a surface using only visible light April 25th, 2017

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

Russian scientists create new system of concrete building structures: Sientists of Peter the Great Saint-Petersburg Polytechnic University developed a new construction technology April 24th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project