Magnetic properties and caloric effect in the Gd(Ni1-x Fex)3 /Cu nanocomposites
|Anna Bajorek 1, Artur Chrobak 1, Grażyna Chełkowska 1, Marzena Kwiecień 1, Małgorzata Karolus 2, Grzegorz Haneczok 2|
1. University of Silesia, August Chełkowski Institute of Physics, Department of Solid State Physics, Uniwersytecka 4, Katowice 40-007, Poland
During the last decades the Greenhouse effect, caused also by emission of chlorofluorocarbons, is considered to be an increasing problem for our environment. One solution for this problem is to eliminate traditional refrigeration by a modern technique based on the magnetocaloric effect (MCE). Materials used for this application should exhibit different opposing properties such as a relatively high magnetocaloric effect, a high thermal conductivity and a Curie point near room temperature. It appears that magnetic nancomposites consisting of rare earth and transition metal particles nanodispersed in a conductive matrix will have great potential for the use in refrigeration. Therefore, the aim of the presented work is to study magnetic properties of the Gd(Ni1-x Fex)3 nanopowder embedded into a copper matrix with a caloric effect of high efficiency near room temperature. Apart from that it is important to compare the magnetic properties of the examined nanocomposites and crystalline phase of the magnetic component.
The Gd(Ni1-x Fex)3 compounds were obtained by arc melting technique, the compounds were ground by making use of mechanical ball milling and finally the mixture of milled nanopowder and copper was compacted. As it is shown the best material for the room temperature refrigeration exhibit samples with 0.1<= x <=0.2 for which the Tc is 266 K and 376 K respectively. However the highest magnetocaloric effect was observed for Ni- rich samples.
Presentation: Poster at E-MRS Fall Meeting 2008, Symposium F, by Anna Bajorek
See On-line Journal of E-MRS Fall Meeting 2008
Submitted: 2008-05-09 12:40 Revised: 2009-06-07 00:48
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