Simple preparation and characterization of nickel ferrite nanocrystals by a thermal treatment method

Abstract

Nickel ferrite nanocrystals were prepared from an aqueous solution containing metal nitrates and poly (vinyl pyrrolidone) (PVP) as a capping agent. To stabilize the particles, they were thermally treated at various temperatures from 623 to 823. K at which calcination occurred, thereby stabilizing the particles, controlling the growth of the nanoparticles, preventing their agglomeration, and creating a uniform distribution of particle sizes. The characterization studies were conducted by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). The crystallization was completed between 723 and 823. K, as revealed by the absence of organic absorption bands in the FT-IR spectra Magnetization measurements were obtained at room temperature by using a vibrating sample magnetometer (VSM), which showed that the calcined samples exhibited ferromagnetic behaviors. Finally, we used TEM images and FT-IR spectra to investigate the same process in the absence of PVP and with various of concentrations of PVP for comparison with the results acquired from using the optimum concentration that was used in this work.

An Overview on Nanocrystalline ZnFe2O4, MnFe2O4, and CoFe2O4 Synthesized by a Thermal Treatment Method

“…The decrease in saturation magnetization of these samples, compared to that of bulk material, depends on four factors explained in Section 3.3. It seems that, in inversed spinel ferrite nanoparticles such as cobalt ferrite or nickel ferrite nanoparticles which fabricated by thermal treatment method, the heating rate of calcination is more important than other parameters that can effectively increase or decrease the saturation magnetization [25,41]. In our experiments, the heating rate of calcination was 10 K/min for cobalt, zinc, and manganese ferrite nanoparticles calcined at 723, 773, 823, and 873 K, which was a medium heating rate.…”

A Novel Research on Behavior of Zinc Ferrite Nanoparticles in Different Concentration of Poly(vinyl pyrrolidone) (PVP)

“…The properties of ferrite nanoparticles can be altered by controlling their size, which can provide an advantage in formulating new composite materials with optimized properties for various applications. Thus, to control the growth of the spinel ferrite nanoparticles, organic stabilizers (polymers), e.g., polyvinyl alcohol (PVA), polyethylene oxide (PEO), polymethacrylic acid (PMAA), and poly(vinyl pyrrolidone) (PVP), are added during the synthesis for capping the surface of the particles [14,15]. In our previous work [16], a thermal-treatment method was used to prepare zinc ferrite (ZnFe 2 O 4 ) nanoparticles from an aqueous solution that contained metal nitrates, PVP, and deionized water.…”

Síntese e caracterização de nanopartículas de NiFe2O4 utilizando o método de sol-gel/combustão e combustão homogênea

“…O tamanho médio de cristalito (D) encontra-se entre 20 e 65 nm. Como pode ser observado na Tabela 1, esses valores estão próximos aos encontrados na literatura [1,3,7]. É possível notar que a amostra SG possui menor (D) quando comparada à CH 1,0 e 1,5, o que demonstra que esse parâmetro depende consideravelmente do método de síntese.…”

“…Devido a propriedades como dureza, alta coercividade e moderada magnetização de saturação, esta ferrita tem sido amplamente estudada. Porém, sabe-se que suas propriedades estão fortemente ligadas a sua composição química, microestrutura e tamanho dos cristalitos, os quais podem ser controlados por meio da forma de preparação [3].…”