LAUSR

Abstract This work presents a rapid and facile method to produce and adjust the magnetic and physical properties of magnetic nanoparticles. SEM and DRX characterizations, as well as magnetic hysteresis curves and magnetic susceptibility curves, were performed to study changes in the nanoparticles as a function of two stirring speeds: 1000 and 3000 rpm. The formation of spherical nanoparticles was observed at both speeds, but the small ones (72 nm) were obtained at the highest stirring speed. However, at this speed, the magnetite nanoparticles showed to be partially oxidized to hematite. Magnetic curves reveal the superparamagnetic and spin-glass behavior of both kinds of nanoparticles. The blocking and irreversibility temperature of the nanoparticles was not perceived even at room temperature.