Effect of size reduction on the magnetic and antibacterial properties of ZnO:Zr:Mn nanoparticles synthesized by a cost-effective chemical method

Zr and Zr + Mn doped ZnO nanopowders were synthesized using a simple soft chemical route keeping the Zr concentration in the precursor solution constant (3 at.%) and varying the Mn concentration (0, 1.5 and 9 at.%). From the X-ray diffraction studies, the crystallite size of ZnO:Zr nanopowder is found as 57 nm. The crystallite size decreases with the increase in the Mn doping level and attains a minimum of 23 nm at the maximum doping level examined in the present work (9 at.%). The Zr doped ZnO nanopowders found to have ferromagnetic property. The saturation magnetization increases with the increase in the Mn doping level and attains a maximum value at 7 at.% of Mn doping. The material shows superparamagnetic behavior at the doping level of 9 at.%. The antibacterial efficiency is found to be maximum at 9 at.% of Mn doping and at this doping level the grain size is minimum (20 nm) as evidenced from the SEM and TEM results.