Synthesis of FeNi nanoparticles by proteic sol-gel process

Full text: Superparamagnetic nanoparticles, due to its properties, have some applications in the medical and biological fields, in which they are used as vectors for drug transport in cancer treatments [1]. FeNi nanoparticles, on the other hand, can also be applied in the catalyst industry [2]. In this work, the formation of FeNi alloy nanoparticles by the proteic sol-gel method was studied as a function of temperature and H₂ flow, and its crystalline characteristics by X-ray diffraction associated with Rietveld refinement. The synthesis was performed with a mixture of iron and nickel solutions and edible bovine gelatin. The polymerization solution was dried in a laboratory oven at 100°C for 72h. After that, the samples were macerated to obtain a fine powder, which was oxidized in air atmosphere (30mL/min) at 700°C. In one set of samples, reductions were made in H₂ atmosphere with flux of 30mL/min at several temperatures (500, 600, 650 and 700°C). In another set, the reductions were carried out also in H₂ atmosphere, but at a temperature of 500°C and distinct flow rates (25, 30, 40 and 50mL/min). Pure alloy was obtained for samples reduced at 650 and 700°C with a flux of 30 mL/min. With respect to variation of the reduced flux, pure alloy was obtained for 40 and 50mL/min. In the other samples there is a mixture of FeNi alloy and NiFe₂O₄. Now the research is focused on the magnetic and morphological properties, to be analyzed by vibrating sample magnetometer, Mössbauer spectroscopy and Scanning Electron Microscopy. References: [1] Challa, S.S.R., Kuma, F. M., Advanced Drug Delivery Reviews, 63 9, 789-808 (2011). [2] Tang, X., Li, L., Shen, B., Wang, C., Chemosphere, 91 9, 13678-1373, (2013). (author)