Polymer matrix templated synthesis: Manganese zinc ferrite nanoparticles preparation

Abstract

Nanoparticles of Mn_xZn_1−xFe₂O₄ where x = 0, 0.4, 0.5 and 0.6 were prepared by polymer matrix templated synthesis method. This technique utilized synthetic ion exchange resin as a host for precipitation of nanoparticles. Mn²⁺, Zn²⁺ and Fe³⁺ were adsorbed into the matrix of the resin from an aqueous solution mixture of respective chlorides. The resin beads were then recovered washed and dried. Follow by an excess amount of NaOH solution added to the resin that contained Mn²⁺, Zn²⁺ and Fe³⁺. The system was then heated to 85°C to transform the precipitated precursors into magnetic oxide. The morphology and shape of the particles were observed by transmission electron microscopy. The particles were almost spherical in shape and were about 6–9 nm in diameter. X-ray diffraction patterns showed broad peaks indicating that the crystallite sizes were in sub-micron dimension. The crystallite sizes for these particles increased with increasing Mn content. Magnetic property measurements were carried out using an alternating gradient magnetometer. The magnetization curves passed through the origin and showed no hysteresis indicating that the particles were superparamagnetic.