Super spin-glass state in two-dimensional aggregated Fe3 O4 nanoparticles deposited on a plasma-treated polymeric substrate

The assembly consisting of Fe3O4 nanoparticles deposited on a plasma-treated polypropylene substrate was structurally characterized and its static and dynamic magnetic properties were investigated. The Fe3O4 nanoparticles of the nominal size of 10 nm create agglomerates of the size ranging from nominally 10 to 400 nm which were deposited on the polypropylene substrate using the grafting technique. The behavior of zero field cooled and field cooled susceptibility was found to be consistent with the onset of the super spin-glass state with glassy temperature Tg=211K. The formation of the super spin-glass state was also supported by the relative shift of maximum in alternating susceptibility Γ ≈ 0.06 and zɛ=8.6 obtained from critical slowing down analysis as well as by the study of memory and aging effects. Significant renormalization of Tg and zυ for obtaining universal behavior in dynamic scaling of alternating susceptibility is tentatively ascribed to deviation toward two-dimensional magnetic behavior. The obtained results suggest that the studied assembly may be appropriate for the realization of unique two-dimensional super spin glass with dominant dipolar interaction.