Crystal structures and magnetic properties of polyethylene glycol/polyacrylamide encapsulated CoCuFe4O8 ferrite nanoparticles

Abstract

Polymer-inorganic nanocomposites with systematized structure provide a novel composite material having complementary between the polymer and inorganic materials. A new CoCuFe 4 O 8 spinel ferrite was prepared by a modified citrate auto combustion technique. The formation of the core-shell structure by coating CoCuFe 4 O 8 nanoparticles (NPs) with Polyethylene glycol (PEG) or Polyacrylamide (PAM) was successfully proceeding. The X-ray diffraction analysis shows that the prepared sample crystallizes in a cubic crystal structure with the Fd3m space group. The structural changes are elucidated via diametrical size, lattice parameter, dislocation density and strain. The obtained data reveals that after coating with PEG/ PAM the crystallite size of CoCuFe 4 O 8 spinel ferrite nanoparticles decreases while, the dislocation density increases. The dislocation density provides more energy-friendly locations for nucleation, consequently, the crystallinity deteriorates and the crystal grains become finer. High-Resolution Transmission Electron Microscopy (HRTEM) images ratify that the spinel nanoparticles are embedded in the PEG/PAM matrix forming the core-shell structure. The measurements of the magnetic hysteresis loops assure that all prepared samples exhibit a hard ferrite nature with a coercivity ranging from 1525 to 1512 Oe. The decrease of the magnetic parameters of CoCuFe 4 O 8 /PEG-PAM can be explained on the basis of the contribution of the non-magnetic coating layer to the total magnetization. The total magnetic behavior of the nanocomposites can be tuned and tailored depending on the coating layers. Based on the obtained data, the formulated CoCuFe 4 O 8 decorated with PEG-PAM can be recognized as a promising functional material for applications in biomedicine. The enhanced magnetic properties make CoCuFe 4 O 8 /PEG-PAM a fitting candidate in the high-density recording.

The role of thermal treatment and formulation on modifying the structural nature and optimizing certain physical features of coprecipitated superparamagnetic Co–Mn–Cr spinel ferrite

“…Furthermore, the magnetic anisotropy field is required to specify the energy needed to change the magnetization direction from the easy direction to the magnetic field direction. It depends strongly on particle size, saturation magnetization, and coercivity [ 76 ]. Therefore, the magneto-crystalline anisotropy constant, K 1 , is an important parameter and was calculated using Brown's relation [ 75 ], where μ 0 = 1 in the CGS system.…”

Innovative Methodology for the Synthesis of CoFe2O4 Encapsulated La2Fe2O6 Nanoparticles for their Use in Various Applications.

“…On the other side, the preparation conditions have the advantage of decreasing the values of the switching eld distribution (SFD) for the core-shell nanoparticles. The SFD is another signi cant magnetic parameter that can be de ned from the following equation [44] SFD = ΔH/H c (1…”

Evaluation of synergistic approach of spinel cadmium–copper nanoferrites as magnetic catalysts for promoting wastewater decontamination: Impact of Ag ions doping

“…Many factors affected ferrite characteristics including preparation conditions, size, microstructure, heat treatment, synthesis method, and cation distribution (Kulkarni and Mathad 2021 ; Rao et al 2020 ). Ferrites have been fabricated with several methods (Amin et al 2021 ; Rao et al 2020 ; Yanjiao et al 2021 ; Kulkarni et al 2019 ; Shahid et al 2017 ; Ateia et al 2020 ; Patila et al 2015 ). The co-precipitation method is one of the best synthesis procedures due to its many benefits, including high homogeneity and small particle size (Nabi et al 2021 ).…”