| Magnetic nanoparticles exhibit superparamagnetic and ferromagnetic behaviors controlled by the particle size and interactions. While monodisperse nanoparticles are of interest from fundamental science perspective, functional nanostructures involve dispersion of particles in host matrices such as polymers. We discuss synthesis and magnetism of polymer nanocomposites based on PMMA with embedded Fe3O4 nanoparticles. An interesting application of nanoparticle assemblies is in magneto-caloric effect (MCE) that has the potential for local cooling/heating of NEMS and MEMS devices. We have studied MCE in CoFe2O4 nanoparticles by measuring family of M-H curves at set temperature intervals and calculated the entropy change (ΔS) for this system. |
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