Fe2O3 and Gd2O3 nanoparticles embedded in mesoporous silica: Magnetic properties comparison

Abstract

Nanocomposite materials containing Fe2O3 and Gd2O3 nanoparticles with the same concentration were prepared by nanocasting method. At this procedure silica matrix serves as nanoreactor for growth of nanoparticles. Temperature and external dc field dependences of the magnetization both samples were compared. Composite containing Fe2O3 nanoparticles shows superparamagnetic behaviour with blocking temperature around 45 K. Otherwise, paramagnetic properties were observed for the sample with Gd2O3 (above 10 K). Additionally, due to free pores the silica matrix could serve as medium to increase the number of bonded water molecules. These properties together with appropriate magnetic characteristics make studied materials suitable for magnetic resonance imaging applications.