Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > A 50-year quest to isolate the thermoelectric effect is now over: Magnon drag unveiled

Abstract:
As electrons move past atoms in a solid, their charge distorts the nearby lattice and can create a wave. Reciprocally, a wave in the lattice affects the electrons motion, in analogy to a wave in the sea that pushes a surfer riding it. This interaction results in a thermoelectric effect that was first observed during the 1950´s and has come to be known as phonon-drag, because it can be quantified from the flow of lattice-wave quanta (phonons) that occurs over the temperature gradient.

A 50-year quest to isolate the thermoelectric effect is now over: Magnon drag unveiled

Bellaterra, Spain | Posted on December 18th, 2011

Soon after the discovery of the phonon drag, an analogous phenomenon was predicted to appear in magnetic materials: the so called magnon drag. In a magnetic material the intrinsic magnetic moment or spin of the electrons arrange in an organized fashion. In ferromagnets, the spins maintain a parallel orientation. If a distortion in the preferred spin orientation occurs, a spin wave is created that could affect electron motion. It is therefore reasonable to expect that the flow of magnons (spin-wave quanta) could also drag the electrons.

Despite the similarities with phonon drag, the observation of the magnon drag has been elusive, and only a few indirect indications of its existence have been reported over the years. The main reason being the presence of other thermoelectric effects, most notably the phonon drag, that make it difficult to discriminate its contribution to the thermopower.

Researchers of ICN´s Physics and Engineering of Nanodevices Group, Marius V. Costache, Germán Bridoux, Ingmar Neumann and group leader ICREA Prof. Sergio O. Valenzuela used a unique device geometry to discriminate the magnon drag from other thermoelectric effects. The device resembles a thermopile formed by a large number of pairs of ferromagnetic wires placed between a hot and a cold source and connected thermally in parallel and electrically in series. By controlling the relative orientation of the magnetization in pairs of wires, the magnon drag can be studied independently of the electron and phonon drag thermoelectric effects.

The work is very timely as thermoelectric effects in spin-electronics (spintronics) are gathering increasing attention as a means of managing heat in nanoscale structures and of controlling spin information by using heat flow. Measurements as a function of temperature reveal the effect on magnon drag following a variation of magnon and phonon populations. This information is crucial to understand the physics of thermal spin transport. It both provides invaluable opportunities to gather knowledge about electron-magnon interactions and may be beneficial for energy conversion applications and for the search of novel pathways towards transporting spin information.

####

For more information, please click here

Contacts:
Prof. Dr. Sergio O. Valenzuela

34-935-814-408

Copyright © Institut Català de Nanotecnologia

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

Fonon Announces 3D Metal Sintering Technology: Emerging Additive Nano Powder Manufacturing Technology August 28th, 2014

Ultra-Low Frequency Vibration Isolation Stabilizes Scanning Tunneling Microscopy at UCLA’s Nano-Research Group August 28th, 2014

Novel 'butterfly' molecule could build new sensors, photoenergy conversion devices August 28th, 2014

New technique uses fraction of measurements to efficiently find quantum wave functions August 28th, 2014

Measure Both Elastic and Viscous Properties with AFM Using Asylum Research’s Exclusive AM-FM Viscoelastic Mapping Mode August 28th, 2014

Physics

New technique uses fraction of measurements to efficiently find quantum wave functions August 28th, 2014

Creation of a Highly Efficient Technique to Develop Low-Friction Materials Which Are Drawing Attention in Association with Energy Issues August 26th, 2014

Discoveries

Novel 'butterfly' molecule could build new sensors, photoenergy conversion devices August 28th, 2014

New technique uses fraction of measurements to efficiently find quantum wave functions August 28th, 2014

The thunder god vine, assisted by nanotechnology, could shake up future cancer treatment: Targeted therapy for hepatocellular carcinoma using nanotechnology August 27th, 2014

Scientists craft atomically seamless, thinnest-possible semiconductor junctions August 26th, 2014

Announcements

Leading European communications companies and research organizations have launched an EU project developing the future 5th Generation cellular mobile networks August 28th, 2014

Ultra-Low Frequency Vibration Isolation Stabilizes Scanning Tunneling Microscopy at UCLA’s Nano-Research Group August 28th, 2014

Novel 'butterfly' molecule could build new sensors, photoenergy conversion devices August 28th, 2014

New technique uses fraction of measurements to efficiently find quantum wave functions August 28th, 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