Abstract
Some manifestations of magnetism are well-known and utilized on an everyday basis, e.g. using a
refrigerator magnet for hanging that important note on the refrigerator door. Others are, so far, more
exotic, such as cooling by making use of the magnetocaloric eect. This eect can cause a change in
the temperature of a magnetic material when a magnetic eld is applied or removed. For many years,
experimentalists have made use of dilute paramagnetic materials to achieve milliKelvin temperatures by
use of the magnetocaloric eect. Also, research is done on materials, which might be used for hydrogen,
helium or nitrogen liquefaction or for room-temperature cooling. The magnetocaloric eect can further be
used to determine phase transition boundaries, if a change in the magnetic state occurs at the boundary.In
this talk, I will introduce the magnetocaloric eect (MCE) and the two equations, which characterize
the eect: the isothermal magnetic entropy change and the adiabatic temperature change. Some of the
manifestations and utilizations of the MCE will be touched upon in a general way and nally I will talk
about the results I have obtained on a sample of Gadolinium Iron Garnet (GdIG, Gd3Fe5O12), which is
a rather complex magnetic system. GdIG has three magnetic sublattices, one Gd and two Fe. The Fe
sites are strongly coupled antiferromagnetically, i.e. the magnetic moments are anti-parallel, while the
Gd magnetic moment is weakly coupled antiferromagnetically to the resulting Fe moment. This results
in a compensation temperature, where the total magnetic moment is zero and my study has focused on
this temperature region.
Original language | English |
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Title of host publication | Program and abstracts |
Publisher | Danish Physical Society |
Publication date | 2010 |
Pages | 57-57 |
Publication status | Published - 2010 |
Event | Danish Physical Society Annual Meeting 2010 - Nyborg, Denmark Duration: 22 Jun 2010 → 23 Jun 2010 |
Conference
Conference | Danish Physical Society Annual Meeting 2010 |
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Country/Territory | Denmark |
City | Nyborg |
Period | 22/06/2010 → 23/06/2010 |
Keywords
- Magnetic refrigeration
- Fuel Cells and hydrogen