Magnetic field-dependence study of the magnetocaloric properties of a superparamagnetic nanoparticle system: a Monte Carlo simulation

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2008-06, Vol.205 (6), p.1349-1353
• Main Authors: Serantes, D., Baldomir, D., Pereiro, M., Rivas, J., Vázquez-Vázquez, C., Buján-Núñez, M. C., Arias, J. E.
• Format: Article
• Language: English
• Subjects: 02.70.Uu; 75.30.Sg; 75.40.Mg; 75.50.Tt; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Diamagnetism, paramagnetism and superparamagnetism; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; Physics
• ISSN: 1862-6300; 0031-8965; 1862-6319
• DOI: 10.1002/pssa.200778149

The influence of the applied magnetic field on the magnetocaloric properties of a fine magnetic particle system has been studied using a Monte Carlo technique. By simulating zero field cooling (ZFC) curves under different strengths of the applied magnetic field, we have analyzed the variation of the entropy for temperatures above the maximum of the ZFC curves, where the process is reversible. The entropy curves have been observed to behave in a different fashion at low values of the magnetic field, where the peak only slightly shifts to higher temperatures with increasing fields. For larger fields, the peak rapidly shifts to higher temperatures, while the overall shape of the curve broadens over a wide temperature range. It is also observed that the blocking temperature as a function of the magnetic field shows the feature of a change from a bell‐like shape to a monotonically decreasing function, resembling what is found experimentally for intermediate values of the sample concentration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)