Abstract:
Ni sub(0.6-x)Zn sub(x)Mn sub(0.4)Fe sub(2)O sub(4)(x=0.0,0.2,0.4,0.6) were prepared by the combustion method using hexamine as the fuel. Zinc replacement in place of Ni and its effect on various structural, electric, magnetic, and dielectric properties was studied using several instrumental techniques. X-ray diffraction revealed a monophasic cubic spinel structure for the samples. Scherrer's formula determined that the crystallite size (D) was in the nano range from 8 to 15 nm. The lattice constant values showed an increment with zinc content while porosity was seen to drop. The scanning electron microscopy images showcased agglomerated particles due to magnetic interaction between them and were found to have spherical morphology. TEM provided the average particle size obtained from the histogram, while the SAED pattern revealed the semicrystalline nature of the samples. Infrared spectra showed two metal-oxygen peaks peculiar to spinel ferrite in the range of approx. 400-600 cm sup(-1). Confirmation of the spinel phase was made using room temperature Raman analysis, and the change in Raman peaks was observed with an increase in zinc content. XPS studies revealed Ni sup(+2), Mn sup(+2), Zn sup(+2), and Fe sup(+3) to be in their respective valence states. A resistivity study was conducted from RT- 500 degrees C, which showed a decrease in resistivity with an increase in temperature, a typical trend of semiconduction. Dielectric studies performed at RT showed the highest dielectric constant with the minimum dielectric loss for sample x=0.2, while variable temperatures studied at different frequencies showed x=0.6 with the highest dielectric constant. Saturation magnetization values increased up to x=0.4, which Neel's two sublattices model explained, and a further decrease in magnetization was explained by the Yafet- Kittle model. AC susceptibility revealed Curie temperature up to the point where the sample behaved as ferrimagnetic material. The main aim and objective were to explore the suitability of synthesized materials for their applications and to study zinc's influence on various properties and antibacterial activity. The antibacterial activity of the samples was investigated as a potential candidate against highly resistant and infectious Staphylococcus aureus, and sample x=0.2 showed the best results.
