Synthesis, self-organization and magnetism of iron oxide and Au-iron oxide core/shell nanocomposite particles

S. SHARMA; D. MURACA; M. KNOBEL; P. MENDOZA ZÉLIS

Barcelona

Conferencia; 20th Intenational Conference on Magnetism; 2015

This work reports a simple chemical synthesis of Au-iron oxide nanocomposites using Au nanoparticles seeds and their systematic oxidation in the presence of dry air atmosphere at various temperatures (125-250 C). It has been observed that the oxidation not only facilitate the self-organization of iron oxide nanoparticles, but also to switch these nanocomposites into core-shell Au-iron oxide structures. We have observed a systematic improvement in the core and shell shape through controlling the reaction time as well as the oxidation temperature.Spherical and spherical-triangle shaped core-shell structures have been synthesized at an optimum oxidation temperature of 125 C and 150 C for 30 minutes, whereas with the further increase in the temperature as well as oxidation time, there is a full amendment in the core-shell structures. The nanoparticle samples have been thoroughly characterized using X-ray diffraction (XRD), high‐resolution transmission electron microscopy (HR-TEM), Mossbauer spectroscopy and superconducting quantum interference device (SQUID) magnetometer.