Tuning the magnetic behavior and improving the antibacterial efficiency of ZnO nanopowders through Zr+Fe doping for biomedical applications

Zr and Zr+Fe co-doped ZnO nanopowders were synthesized using a simple soft chemical method keeping the doping level of Zr as constant (3 at%) and varying the doping level of Fe (1,5and 10 at%) in the precursor solution. The XRD studies reveal that the synthesized nanopowders exhibit hexagonal wurtzite structure of ZnO. The crystallite size of ZnO:Zr nanopowders is found to be 63 nm and then the size decreases gradually with the increase in the Fe doping level and attains a minimum of 28 nm at 10 at% of Fe doping level. The Zr doped ZnO nanopowders are found to have ferromagnetic property. The material exhibits paramagnetic nature up to 5 at% of Fe doping level. At 10 at% of Fe doping level superparamagnetic behavior is observed. The antibacterial efficiency against two different bacterial strains viz Bacillus subtilis and Escherichia coli is studied. The antibacterial efficiency is found to be the maximum at 10 at% of Fe doping level.