Blocking temperatures of amorphous iron nanoparticles coated by various surfactants

Abstract Amorphous iron nanoparticles obtained by the sonication of Fe(CO) 5 in decalin were coated by various surfactants using the self-assembled monolayer (SAM) technique. They have been shown previously to behave as superparamagnetic materials. These measurements are now extended to include information regarding their blocking temperature ( T B ). The results show that for one functional group T B is only slightly dependent on the length of the alkyl chain. On the other hand, the nature of the functional group bonded to the iron particles is strongly affecting T B .