Blocking temperatures of amorphous iron nanoparticles coated by various surfactants

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 (TB). The results show that for one functional group TB 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 TB.