Influence of Laser Ablation Energy on Structural and Optical Properties of CoLa_0.02Fe_1.98O₄ Nanoferrite for Bioactivity Application

The internal combustion method and pulsed laser ablation were used to prepare cobalt lanthanum nanoferrite, respectively, in sequence. Laser energy has been changed from 500 to 700 mJ when preparing the nanoferrite and studying its effect on the properties. The structure, optical, and morphological properties of the nanoferrite using XRD, FTIR, UV-vis, and FESEM have been studied. The prepared nanoferrite at 500 mJ showed a cubic spinel La-doped CoFe₂O₄ ferrite with the hematite phase that depressed after increasing the laser energy to 700 mJ. The Williamson–Hall plot was adopted to calculate the crystallite size and the internal stress of the nanoferrite. The results showed that the crystallite size in the case of using 500 mJ is 36 nm, while the laser energy increases to 700 mJ leading to a crystallite size of 15 nm. The bandgap of the prepared nanoferrite showed significant change with increasing laser energy according to the UV-Vis result. A vibration band of the stretching of oxygen bonds of nanoferrite is located at the tetrahedral site as shown in the FTIR result and is not changed according to laser energy variation. A colloidal CoLa_0.02Fe_1.98O₄ prepared at 500 and 700 mJ has higher antioxidant activity, after being used as a scavenger of the DPPH free radical. This ability indicates the interaction and neutralizes free radicals to prevent them from causing damage.