Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Spintronic Thermoelectric Power Generators: A step towards energy efficient electronic devices

Schematic of the spintronic thermoelectric device fabricated by the University of Utah’s researchers. This device can convert even minute heat emitted by hand-held electronic devices such as laptops, etc. into useful electricity.

Image Credit: Courtesy of Gene Siegel and Shiang Teng, University of Utah
Schematic of the spintronic thermoelectric device fabricated by the University of Utah’s researchers. This device can convert even minute heat emitted by hand-held electronic devices such as laptops, etc. into useful electricity.

Image Credit: Courtesy of Gene Siegel and Shiang Teng, University of Utah

Abstract:
Imagine a computer so efficient that it can recycle its own waste heat to produce electricity. While such an idea may seem far-fetched today, significant progress has already been made to realize these devices. Researchers at the Nanostructured Materials Research Laboratory at the University of Utah have fabricated spintronics-based thin film devices which do just that i.e., convert even minute waste heat into useful electricity.

Spintronic Thermoelectric Power Generators: A step towards energy efficient electronic devices

Salt Lake City, UT | Posted on March 21st, 2014

"As electronic devices enter the nano-size regime, the problem of heat generation is becoming more and more severe," says University of Utah Materials Scientist Ashutosh Tiwari, who led the research published online Friday, March 21 in the Nature publishing group's journal "Scientific Reports".

"Our spintronic-based thermoelectric devices work at room temperature and doesn't require the continuous application of external magnetic field," Tiwari says. "Most of the spintronic thermoelectric devices in earlier studies required the continuous application of a magnetic field to keep the device magnetized."

"Spintronics is a new branch of electronics which utilizes both the charge as well as the spin of electrons," says Tiwari.

Tiwari conducted the research with graduate students Gene Siegel, Megan Campbell Prestgard and Shiang Teng. The study was funded by the U.S. National Science Foundation's Condensed Matter Physics Program, Sensors and Sensing Systems Program and the University of Utah's Materials Research Science and Engineering Center.

"The most important and fascinating aspect of our study is that these devices are not made of traditional thermoelectric materials which, when heated, generate a voltage simply because of the movement of charge carriers. This, known as Seebeck effect, has a fundamental limitation," says Tiwari. "Specifically, for achieving practically acceptable heat-to-electricity conversion efficiency, the electrical conductivity of the thermoelectric material should be maximized while its thermal conductivity should be simultaneously minimized. These two requirements are contradictory."

He adds, "Our spintronic-based devices are based on an altogether different concept known as spin-caloritronics. Here, thermal and electrical transport occurs in the different parts and hence these devices are not plagued by the problems encountered by their traditional counterparts."
Experiment

For making spintronic thermoelectric devices, Utah researchers deposited thin films of a material know as bismuth-doped YIG (Bi-YIG) using a 25 nanosecond pulsed laser. Over the Bi-YIG film, a 10 nm thick layer of platinum was deposited using a beam of electrons. The bi-layer structure thus prepared was kept in a magnetic field for a few minutes to magnetically polarize Bi-YIG film. After this, the external magnetic field was removed and a temperature gradient was applied across the bilayer. This temperature difference leads to a current of low-lying excitations of localized spins, known as magnons, in the Bi-YIG. When this magnon current enters in the platinum layer, it is converted into a charge voltage through a process named as the inverse-Hall effect, explains Gene Siegel, first author of the paper.

The researchers' trick was to generate very large roughness on the surface of the Bi-YIG films by using very high energy density laser pulses. Rough surfaces resulted in very large stray fields, which gave rise to large magnetic coercevity in the films. Because of the large corecivity, once these devices are magnetized they remain magnetized and don't require any external field for operation, says Siegel.

"Our experimental findings are in excellent agreement with the predictions of the Magnon transport theory," says Tiwari.

"Tiwari's group's research opens the doors for the development of spin-driven thermoelectrics which can turn waste heat into electricity, and make efficient electronic devices," says Ajay Nahata, Director of the University of Utah's NSF MRSEC on Next Generation Materials for Plasmonics & Organic Spintronics.

####

For more information, please click here

Contacts:
Ashutosh Tiwari
associate professor of materials science and engineering
Phone: 801-585-1666


Aditi Risbud
senior communications and marketing officer
University of Utah College of Engineering
Office Phone: 801-587-9038
Cell Phone: 213-400-5815

Copyright © University of Utah

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

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Thin films

Beneq launches nFOG™ wet coating technology September 3rd, 2014

Picosun joins forces with IMEC for novel, industrial ALD applications August 25th, 2014

An Inkjet-Printed Field-Effect Transistor for Label-Free Biosensing August 11th, 2014

Advanced thin-film technique could deliver long-lasting medication: Nanoscale, biodegradable drug-delivery method could provide a year or more of steady doses August 6th, 2014

Spintronics

A new, tunable device for spintronics: An international team of scientists including physicist Jairo Sinova from the University of Mainz realises a tunable spin-charge converter made of GaAs August 29th, 2014

Molecular engineers record an electron's quantum behavior August 14th, 2014

Diamond defect interior design: Planting imperfections called 'NV centers' at specific spots within a diamond lattice could advance quantum computing and atomic-scale measurement August 5th, 2014

University of Illinois study advances limits for ultrafast nano-devices July 10th, 2014

Chip Technology

‘Small’ transformation yields big changes September 16th, 2014

UT Arlington research uses nanotechnology to help cool electrons with no external sources September 11th, 2014

Excitonic Dark States Shed Light on TMDC Atomic Layers: Berkeley Lab Discovery Holds Promise for Nanoelectronic and Photonic Applications September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

Discoveries

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Announcements

New NPZ100-403 Piezo Stage from nPoint Inc. September 17th, 2014

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Energy

Rice rolls 'neat' nanotube fibers: Rice University researchers' acid-free approach leads to strong conductive carbon threads September 15th, 2014

Simple, Cost-Effective Method Proposed for Synthesizing Zinc Oxide Nanopigments September 15th, 2014

UT Arlington research uses nanotechnology to help cool electrons with no external sources September 11th, 2014

Excitonic Dark States Shed Light on TMDC Atomic Layers: Berkeley Lab Discovery Holds Promise for Nanoelectronic and Photonic Applications September 11th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE