Magnetic Properties of Fe-Pd Alloy Nanoparticles

Pd nanoparticles (2 nm in diameter) containing magnetic Fe atoms are prepared and their magnetic properties are investigated. The magnetic moment of the particles is enhanced in the low Fe concentration region and takes a maximum value of 7.6 mu(B) per Fe atom at the concentration in which each Pd nanoparticle contains one Fe atom on average. This giant magnetic moment is explained in terms of the spin polarization on Pd atoms caused by the exchange enhancement mechanism. The magnetization curve shows that these Fe Pd alloy nanoparticles exhibit superparamagnetic behavior, although no blocking behavior in the temperature dependence of the magnetic susceptibility was observed due to the small magnetic anisotropy of Fe.