Morphological Structure, Optical and Microbial Findings of Ferrites

In this article, we report the interesting results on the effect of high energy ball milling (under 350 rpm for 0, 1, 3, 5, and 10 h) on the salt (NaCl:KCl) flux synthesized SrFe₁₂O₁₉ powder. The different processed powder was analyzed by powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTA), field emission scanning electron microscope (FESEM), Fourier-transform infrared (FT-IR) and near infra-red (NIR) reflectance spectroscopic techniques. From the present research findings, we note that the SrFe₁₂O₁₉ phase is susceptible to the high-energy ball milling process. The unmilled SrFe₁₂O₁₉ powder crystallized in hexagonal structure with the platelet-shaped SrFe₁₂O₁₉ grains exhibits high near-infrared (NIR) reflectance. The average crystalline size (XRD) of the unmilled (84.9 nm) SrFe₁₂O₁₉ powder is reduced to 22.2 nm after 1 h of ball milling. Ball milling of good quality SrFe₁₂O₁₉ powder for >1 h, mixed nanocrystalline phases of SrFe₁₂O₁₉ and α-Fe₂O₃ materials are formed. By increasing the ball milling time, the thermal features also vary accordingly. The platelet-shaped SrFe₁₂O₁₉ grains are strongly affected by ball milling of the salt flux synthesized SrFe₁₂O₁₉ powder for 1, 3, 5 and 10 h. Ball milling of SrFe₁₂O₁₉ powder has a strong effect on the NIR reflectance and color of the resultant ball-milled powders. The 1 h as-milled powder shows relatively strong inhibition zone as compared to other powder samples (0, 3, 5, 10 h) against Pseudomonas aeruginosa bacterium.