Synthesis of α-Fe particles using a modified metal-membrane incorporation technique

Abstract

We describe the synthesis of α-Fe particles using a modified metal-membrane incorporation technique based on diffusing metal ions through a dialysis membrane. The diffusion-time was varied up to 15 min. The samples were characterized using X-ray diffraction and scanning electron microscopy (SEM). The average diameter of the α-Fe crystallites was found to vary in the range 17–26 nm depending on the diffusion-time. The hysteresis loops were measured at room temperature while the zero-field-cooled (ZFC) and field-cooled (FC) magnetizations were measured down to 2 K. Both, the remanent magnetization and the coercive field were found to vary with the orientation of the applied magnetic field with respect to the membrane. An irreversible behavior in the ZFC and FC magnetization was also observed. The results are in good agreement with those expected for a three–dimensional (3D) system of nanoparticles with uniaxial anisotropy.