Scientists Generate Magnetic Field by Using Heat Instead of Electricity

*In a newly published study, EPFL [ *Ecole Polytechnique Fédérale de
Lausanne ] *scientists have for the first time predicted and experimentally
verified the existence of the Magnetic Seebeck Effect.*

EPFL scientists have provided the first evidence ever that it is possible
to generate a magnetic field by using heat instead of electricity. The
phenomenon is referred to as the Magnetic Seebeck effect or
‘thermomagnetism’.

A temperature difference across an electric conductor can generate an
electric field. This phenomenon, called the Seebeck effect, lies at the
root of thermoelectricity (heat turned into electricity), and is used to
drive space probes and power thermoelectric generators, and could be
implemented for heat-harvesting in power plants, wrist-watches and
microelectronics. In theory, it is also possible to generate a magnetic
field by using a temperature difference across an electrical insulator
(‘thermomagnetism’). This has been referred to as the Magnetic Seebeck
effect, and has enormous applications for future electronics such as
solid-state devices and magnetic-tunnel transistors. In a breakthrough
Physical Review Letters
publication<http://prl.aps.org/abstract/PRL/v111/i8/e087205> that
has been promoted to “Editors’ Suggestion”, EPFL scientists have for the
first time predicted and experimentally verified the existence of the
Magnetic Seebeck effect.

*Thermoelectricity and ‘thermomagnetism’*

The Seebeck effect (thermoelectricity) – named after Thomas Johann Seebeck
who first observed it in 1821 – is generated when electrons in an electric
conductor move as a response to a temperature gradient. On average, the
electrons on the hot side of the conductor have more kinetic energy and
subsequently move at higher speeds than the electrons on the cold side.
This causes them to diffuse from the hot to the cold side, generating an
electric field that is directly proportional to the temperature gradient
along the conductor.

Using an electrical insulator rather than a conductor, researchers led by
Jean-Philippe Ansermet at EPFL have shown that a Magnetic Seebeck effect
also exists. Because an insulator does not allow electrons to flow, a
temperature gradient does not cause electrons to diffuse. Instead, it
affects another property of electrons that forms the basis of magnetism and
is referred to as ‘spin’...

http://scitechdaily.com/scientists-generate-magnetic-field-using-heat-instead-electricity/

Reply via email to