In Situ Electron Diffraction Investigation of Solid State Synthesis of Co-In2O3 Ferromagnetic Nanocomposite Thin Films

Abstract

In situ electron diffraction was used to study structural transformations during the formation of Co-In2O3 ferromagnetic anocomposite thin films in a thermite reaction of In/Co3O4 bilayer thin films. Heating was performed from room temperature to 600 C at a rate of 4 C/min, while simultaneously electron diffraction patterns were recorded at a speed of 4 frames/min. This made it possible to determine the initiation, 185 C, and finishing, 550 C, temperatures of the solid-state synthesis, as well as the change in he phase composition during the thermite reaction. The synthesized Co-In2O3 film nanocomposite contained ferromagnetic cobalt anoclusters surrounded by an In2O3 layer, with an average size of 20 nm, and had a magnetization of 400 emu/cm3 and coercivity of 50 Oe at room temperature. The estimate of the effective interdiffusion coefficient of the reaction suggests that the main mechanism for the formation of the Co-In2O3 nanocomposite is diffusion along the grain boundaries and dislocations.

formation of the Co-In2O3 nanocomposite is diffusion along the grain boundaries and dislocations.