Thermal Stabilization of Magnetic Nanoparticles Embedded in a Ferromagnetic Matrix, , Nanotechnology

J. M. VARGAS; J. GÓMEZ; R.D. ZYSLER; A. BUTERA

NANOTECHNOLOGY

IOP PUBLISHING

Año: 2007 vol. 18 p. 115714 - 115714

0957-4484

We have developed an alternative method for building up a nanogranular system and have analysed its magnetic properties. Using a chemical route we have obtained magnetite nanoparticles with an average diameter of 4.5 nm and with a very narrow size distribution (ó 20%). These particles have been studied dispersed in a polymer, in powder form, and embedded in a permalloy ferromagnetic matrix which was deposited by sputtering techniques. DC magnetization and electron spin resonance were employed for analysing the magnetic response in these samples, showing a very good agreement with the structural characterization. The thermal stability has been probed in the three systems and the magnetic measurements allowed us to estimate a threefold increase in the energy barrier when the particles are immersed in a ferromagnetic host.ó 20%). These particles have been studied dispersed in a polymer, in powder form, and embedded in a permalloy ferromagnetic matrix which was deposited by sputtering techniques. DC magnetization and electron spin resonance were employed for analysing the magnetic response in these samples, showing a very good agreement with the structural characterization. The thermal stability has been probed in the three systems and the magnetic measurements allowed us to estimate a threefold increase in the energy barrier when the particles are immersed in a ferromagnetic host.