Ferromagnetic-Like Behavior of Pt Nanoparticles

Abstract:

The magnetic properties of small 4d, 5d metal nanoparticles of Pd, Pt (clusters) are attracting a great attention because these materials in bulk are paramagnetic. In this work we report the ferromagnetic-like behavior of the small Pt nanoparticles prepared by chemical method. Highly dispersed Pt clusters have been synthesized on the surfaces of a porous spherical γ-Al₂O₃ particles. The process of the chemical deposition of metalorganic fluid with employment of the supercritical fluid was used. The samples of the Pt/γ-Al₂O₃ nanoparticles have been prepared in INEOS RAS. The nanoparticles size distribution was determined by small-angle X-rays scattering (SAXS). It was found that the Pt clusters have a bimodal particle size distribution with two peaks: R1max=20 Å and R2max=40 Å. The magnetic properties of the clusters have been investigated, using VSM magnetometer, in magnetic field up to ±3 kOe and at a temperature range from 80 to 400 K. It was observed that Pt/γ-Al₂O₃ nanoparticles show the ferromagnetic-like behavior in whole specified temperature range, the value of coercivity decreases gradually from 130 Oe to 80 Oe. The origin of ferromagnetic-like behavior of the Pt/γ-Al₂O₃ nanoparticles is discussed.

• Periodical: Solid State Phenomena (Volume 190)
• Pages: 443-446
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.190.443
• Online since: June 2012
• Authors: S. D. Antipov, G. E. Gorunov, N. S. Perov, M. N. Pivkina, E. E. Said-Galiyev, A.S. Semisalova, P. N. Stetsenko
• Keywords: Chemical Method, Ensemble of Clusters, Ferromagnetic-Like Behavior, Magnetism, Nanoparticle, Stoner Criterion

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