The effect of NaCl prepared by ultra-sonic vibration on Sintering of annealed FePt nanoparticles

Abstract

FePt nanoparticles were synthesis via high-temperature solution phase. Monodispersed 3.5 nm FePt nanoparticles were first obtained by reduction of FeCl2.4H2O and Pt(acac)2. These preformed FePt nanoparticles were then combined with NaCl to prevent from sintering after annealing. The 1 micron salt particles were fabricated by ultra-sonic vibration method and used as the separating media. Annealing studies show that these salt-matrix FePt nanoparticles are stable after annealing at 700 °C for 4 h. The annealed FePt particles diameter increases from 4 to 25 nm as observed by TEM. The magnetic properties are largely affected by annealing temperature. The role of these salt particles on sintering of annealed FePt nanoparticles has been investigated. © 2009 IOP Publishing Ltd.