Experimental and Theoretical Investigations of Magnetic Properties of Co Ferrite/Polyvinyl Alcohol Nanocomposites

Cobalt ferrite nanoparticles (NPs) have been synthesized by the modified co-precipitation technique in the presence of the polyvinyl alcohol (PVA) matrix. The structural and magnetic properties of NPs are tunable by means of interaction between the polymer and the surface of NPs. Magnetic properties of NPs were simulated using the accurate Monte Carlo (MC) method. In addition, the magnetic anisotropy constant has been obtained by means of the law of approach to saturation magnetization (LAS). The experimental and theoretical results are in good agreement with each other and show that the as-synthesized NPs are single domain and approximately non-interacting. The anisotropy constant and size of the NPs increase by increasing the concentration of precursors in the reaction medium. Nanocomposites have been characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Hysteresis loops were investigated at room temperature using a vibrating sample magnetometer (VSM). The crystallite size of single-domain NPs is lower than 20 nm, and the obtained results from FT-IR confirmed the interaction between PVA and the surface of the particles. These approximately non-interacting NPs are useful for magnetic data storage.