Influence of Mn2+ substitution with Co2+ on structural, morphological and coloristic properties of MnFe2O4/SiO2 nanocomposites

The paper presents the structural, morphological and coloristic properties of Co2+ substituted Mn ferrite embedded in SiO2 matrix, obtained by sol-gel method. The thermal analysis showed the precursor formation and the decomposition temperatures, while the structure (crystallite size, density, porosity, lattice constant, unit cell volume) and morphology of the nanocomposites (NCs) were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Fourier transformed infrared spectroscopy confirmed the formation of succinates and their decomposition into ferrites. The potential application of synthesized NCs as pigments in the ceramic industry was tested by their incorporation in glazes, followed by color's assessment using Cielab coordinates. The results revealed that the NCs are stable after 400 degrees C, as no other process take place in the pigments and the mass loss decreases with the increasing Mn2+ substitution by Co2+. Also, the particle size and porosity decrease with the increasing Mn2+ substitution by Co2+. Single crystalline phase was remarked only in case of sample with the highest substitution of Mn2+ with Co2+. The obtained nanoparticles are of dark blue color that by their incorporation in glaze becomes different shades of blue, depending on the Mn2+ substitution by Co2+. By adjusting the Mn2+ substitution by Co2+ in the NC and the synthesis parameters, the obtained NCs may be used in the ceramic industry as pigments.

Automated summary

The paper investigates the structural, morphological, and color properties of Co2+-substituted Mn ferrite embedded in an SiO2 matrix and their potential application as pigments in the ceramic industry. It was found that the nanocomposites are stable after 400 degrees Celsius, with color loss decreasing and particle size and porosity decreasing as the Mn2+ substitution by Co2+ increases. Single crystalline phase was only observed in the sample with the highest Mn2+ substitution by Co2+, and the synthesized nanoparticles exhibit a dark blue color that varies in shades based on the Mn2+ substitution by Co2+.