Back to Search
Start Over
Magnetic entropy changes in nanogranular Fe:Ni61Cu39.
- Source :
- Journal of Applied Physics; Apr2011, Vol. 109 Issue 7, p07A936-07A936-3, 1p
- Publication Year :
- 2011
-
Abstract
- Artificial environment-friendly Gd-free magnetic nanostructures for magnetic cooling are investigated by temperature-dependent magnetic measurements. We consider two-phase nanocomposites where nanoclusters (Fe) are embedded in a Ni61Cu39 matrix. Several composite films are produced by cluster deposition. The average Fe cluster size depends on the deposition conditions and can be tuned by varying the deposition conditions. The quasiequilibrium Curie temperature of the Fe particles is high, but slightly lower than that of bulk Fe due to finite-size effects. Our experiments have focused on ensembles of 7.7 nm Fe clusters in a matrix with a composition close to Ni61Cu39, which has a TC of 180 K. The materials are magnetically soft, with coercivities of order 16 Oe even at relatively low temperature of 100 K. The entropy changes are modest, -ΔS = 0.05 J/kg K in a field change of 1 T and 0.30 J/kg K in a field change of 7 T at a temperature of 180 K, which should improve if the cluster size is reduced. [ABSTRACT FROM AUTHOR]
- Subjects :
- GADOLINIUM
NANOSTRUCTURES
ENTROPY
MAGNETIC materials
ADIABATIC demagnetization
Subjects
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 109
- Issue :
- 7
- Database :
- Complementary Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 86445119
- Full Text :
- https://doi.org/10.1063/1.3562254