Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Thin films

Phonons, arise! Small electric voltage alters conductivity in key materials April 22nd, 2015

Better battery imaging paves way for renewable energy future April 20th, 2015

Cobalt film a clean-fuel find: Rice University discovery is efficient, robust at drawing hydrogen and oxygen from water April 15th, 2015

The microscopic topography of ink on paper: Researchers have analyzed the varying thickness of printed toner in unprecedented 3-D detail, yielding insights that could lead to higher quality, less expensive and more environmentally-friendly glossy and non-glossy papers April 14th, 2015

Spintronics

Drexel materials scientists putting a new spin on computing memory April 22nd, 2015

On the road to spin-orbitronics: Berkeley Lab researchers find new way to manipulate magnetic domain walls April 13th, 2015

Graphene looking promising for future spintronic devices April 10th, 2015

Magnetic vortices in nanodisks reveal information: Researchers from Dresden and Jülich use microwaves to read out information from smallest storage devices March 4th, 2015

Chip Technology

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Drexel materials scientists putting a new spin on computing memory April 22nd, 2015

Printing Silicon on Paper, with Lasers April 21st, 2015

Advances in molecular electronics: Lights on -- molecule on: Researchers from Dresden and Konstanz succeed in light-controlled molecule switching April 20th, 2015

Discoveries

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Announcements

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Energy

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

'Holey' graphene for energy storage: Charged holes in graphene increase energy storage capacity April 22nd, 2015

Expanding the reach of metallic glass April 22nd, 2015

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