T. Veeramani^1,, C. Venkataraju^1,*,, V. Porkalai^1, and R. Sagayaraj^2,*,

¹P.G. & Research Department of Physics, Thiru.Vi.Ka. Government Arts and Science (Affiliated to Bharathidasan University), Thiruvarur-610003, India

²P.G. & Research Department of Physics, St. Joseph’s College of Arts and Science (Autonomous) (Affiliated to Annamalai University), Cuddalore-607001, India

*Corresponding authors: E-mail: tvkphymani@gmail.com; sagayarajnancy@gmail.com

Zinc oxide doped magnesium ferrite (Mg_1-xZn_xFe₂O₄) nanocomposite was synthesized using sol-gel method and demonstrated to have a cubic spinel structure, with a range of crystallite sizes (19-40 nm) and lattice constants (8.432-8.399 Å). The material was found to have two prominent vibrational modes for tetrahedral (446 cm^–1) and octahedral (584 cm^–1). The dielectric constant was higher at low frequencies and decreased at higher frequencies, while the saturation magnetization decreased (16 to 6 emu/g) gradually with an increase in Zn²⁺, likely due to the presence of non-magnetic Zn²⁺. The magneto-dielectric constant was found to increase with the magnetic field for MgFe₂O₄ and up to a magnetic field of 2000 Oe for the zinc magnesium nanocomposites, after which it decreased for higher magnetic fields. A positive and negative change in magneto-capacitance as a function of the magnetic field was also observed. The antibacterial activity suggests that the substitution of Zn²⁺ into magnesium ferrite can be an effective method for improving antibacterial activity, with the potential to damage the bacterial membrane and other components through positively charged ions and ROS generated by nanoparticles. Potential uses for this synthetic material include magneto-optical recording and magnetic biosensors.

Zinc oxide, Magnesium ferrite, Sol-Gel method, Dielectric constant, Magneto dielectric, Coercivity, Ferrimagnetic.