LAUSR

Naked, polyvinylchloride (PVC)-coated, and polyethylene glycol (PEG)-coated Fe3O4 nanoparticles (NPs) with an equivalent average particle size of 10 nm were prepared through an electrochemical synthesis method. The structural and magnetic properties were investigated systematically. The X-ray diffraction study coupled with the Rietveld refinement of XRD data showed that samples are crystallized in cubic spinel structure with space group referred to as Fd3m. The nature of DC magnetization versus field M (H) plot for sample resembles qualitatively with ferromagnetic (FM) systems. The AC-susceptibility data obtained at different frequencies confirmed the presence of a frequency-dependent freezing temperature. Based on the interparticle interaction strength and phenomenological models (Néel–Brown, Vogel–Fulcher, and critical slowing down), the magnetic dynamic behavior of nanoparticles was characterized. By fitting the experimental data with mentioned models, the possibility existence of superparamagnetic and a spin-glass state at low temperatures was proposed for the samples. Also, the obtained values from fitting performance showed a coating effect on interparticle interaction for PVC- and PEG-coated Fe3O4 nanoparticles.