Liu, X. G. and Geng, D. Y. and Jiang, J. J. and Li, B. and Ma, S. and Li, D. and Liu, W. and Zhang, Z. D. (2010) Magnetic properties and large cryogenic low-field magnetocaloric effect of HoCo2 nanoparticles without core/shell structure. Journal of Nanoparticle Research, 12 (4). pp. 1167-1172.
The HoCo2 nanoparticles are found to be stable in air without any shell protection. The HoCo2 nanoparticles display superparamagnetic properties between their blocking temperature of 40 K and Curie temperature of 78 K. The magnetic-entropy change increases with decreasing temperature at a certain magnetic-field change, which is ascribed to the competition between the Zeeman energy and thermal-agitation energy at low temperatures. A large magnetic-entropy change of 19.4 J kg−1 K−1 was found at 7.5 K in an applied-field change from 1 to 7 T, while 6.1 J kg−1 K−1 was achieved in a low field change of 1 T. HoCo2 nanoparticles are useful for application of magnetic refrigeration at low temperatures.
|Subjects:||Physical Science > Nanomagnetics|
Material Science > Nanostructured materials
|Deposited On:||07 Jul 2010 12:12|
|Last Modified:||19 Aug 2010 13:29|
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