EFFECT OF PARTICLE-SIZE AND SURFACE-CHEMISTRY ON THE INTERACTIONS AMONG FINE METALLIC PARTICLES

The effect of different particle size (50-350 angstrom) and surface passivation on the magnetic behavior including interactions has been studied and corelated in Fe and Co particles. The effect of packing fraction on the above properties has also been investigated. The dc remanence (IRM and DCD) and DELTAM curves have been used to calculate various interaction parameter and quantify them, respectively. Strong exchange coupling at the core-shell interface (intra-particle interactions) has a higher contribution to the overall interactions than the interparticle dipolar interactions, especially ln the smaller particles.