Influence of Co over magnetically benign Zn ferrite system and study of its structural, dielectric, superparamagnetic and antibacterial efficacy

Abstract A series of nano-sized Co-Zn ferrite, CoxZn1-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) was synthesized by precursor combustion method. The phase purity, composition, surface area, and oxidation states of corresponding metal ions were confirmed by using the techniques such as X-ray powder diffraction, infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, inductive coupled plasma-atomic emission spectroscopy, Brunauer–Emmett–Teller surface area measurement, and X-ray photoelectron spectroscopy. The transmission electron microscopy analysis revealed cuboidal shaped ferrite particles with 20−30 nm size. The dielectric studies with change in frequency and temperature, and magnetization studies with a change in temperature and applied field, exhibited marked enhancement with cobalt content in the ferrites. The transition from paramagnetic to superparamagnetic nature with rising cobalt content was observed in our investigation based on magnetization and supported by Mossbauer studies. The synthesized ferrites also revealed good antimicrobial activity against gram-negative E. coli ATCC 8439.