Mixture of silver and iron oxide nanoparticles produced by chemical methods

Abstract

A mixture of silver and iron oxide nanoparticles were synthesized by the reaction of FeSO4, AgNO3, and N2H4 in the presence of gelatin at room temperature. The silver/iron oxide nanoparticles were subsequently examined using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Mossbauer spectroscopy. TEM observations revealed two distinct sizes of nanoparticles. The small nanoparticles with diameters of less than 10 nm were assigned to maghemite, and the large particles with diameters of approximately 20 nm were assigned to metallic silver. A Mossbauer spectrum of the maghemite nanoparticles at room temperature showed superparamagnetic behavior due to the small particle sizes. The Mossbauer spectrum measured at low temperature showed a magnetic sextet and a component of distributed hyperfine magnetic fields (DHMF). The DHMF component corresponded to the surface or defects of the maghemite nanoparticles. Silver enhanced the production of maghemite nanoparticles, and the size of the maghemite particles could be controlled by varying the amount of silver salt.