Synthesis, characterization and magnetic properties of amorphous nanoparticles of FeMB (M = transition metal)

We prepared amorphous Fe80-xMxB20 nanoparticles (M=Ni,Mn,Cr) by chemical re duction, were done their structural and morphological characterization and the study of their magnetic properties. The results show that the mean part icle size is composition dependent, increasing with decreasing Fe compositi on. From the magnetic properties we can observe the coexistence of ferromag netic, antiferromagnetic and paramagnetic states. The magnetic field depend ence of the magnetization is irreversible and the temperature dependence wa s done in the field cooled (FC) and a zero field cooled (ZFC) conditions, s howing a wide curve because the particle sizes distribution, small values o f the coercitivity (H-i) and remanent magnetization (M-r) were obtained, sh owing a dependence with temperature.