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-In 2 O 3 ferromagnetic nanocomposite thin films in a thermite reaction of In/Co 3 O 4 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 the phase composition during the thermite reaction. The synthesized Co-In 2 O 3 film nanocomposite contained ferromagnetic cobalt nanoclusters surrounded by an In 2 O 3 layer, with an average size of 20 nm, and had a magnetization of 400 emu/cm 3 and a 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-In 2 O 3 nanocomposite is diffusion along the grain boundaries and dislocations.

Solid-State Reaction in Cu/a-Si Nanolayers: A Comparative Study of STA and Electron Diffraction Data

“…The analysis of the obtained electron diffraction patterns allowed determining the sequence of phase transformations occurring in the solid-state reaction between dissimilar nanolayers. The authors successfully used the method to investigate the process of phase formation during the solid-state reaction in different thin-film nanosystems: Al/Cu [ 25 , 26 ], Al/Pt [ 27 ], Al/Ag [ 28 , 29 ], Cu/Au [ 30 ], Al/Fe [ 31 ], Fe/Si [ 32 ], Fe/Pd [ 30 , 33 , 34 ], Fe-ZrO 2 [ 35 ], Co-ZrO 2 [ 36 ], and Co-In 2 O 3 [ 37 ]. In the present study, in order to estimate the kinetic parameters of the solid-state reaction (activation energy, pre-exponential factor, and reaction order), a series of heating procedures was performed at different rates.…”

In Situ Electron Diffraction and Resistivity Characterization of Solid State Reaction Process in Cu/Al Bilayer Thin Films

“…[30,31] This above-mentioned method was successfully used by the authors for the research of structural phase transformations occurring in the solid state reaction process in various thin film nanosystems: Cu/Au, [32] Al/Pt, [33] Fe/Pd, [32,34,35] Fe/Si, [36] Fe-ZrO 2 , [37] Co-ZrO 2 , [38] Co-In 2 O 3 . [39] In order to carry out in situ experiments with heating in the transmission electron microscope, the samples deposited on NaCl, immediately after the deposition, were separated from the substrate by submerging them into aquabidest for several seconds, then the films rose to the surface and were placed onto a molybdenum TEM support grid, with the remaining water being immediately removed with filter paper. The absence of defects (exfoliation) in the films after placing them onto the grid was controlled with an optical microscope Nikon Eclipse LV 100.…”

Indium Oxide Based Nanomaterials: Fabrication Strategies, Properties, Applications, Challenges and Future Prospect

“…Synthesis of pure In 2 O 3 nanoparticles had been performed via solid state reaction method for the fabrication of optoelectronic devices by Jothibas et al [57]. Moreover, Bykova et al [58] reported Co-In 2 O 3 nanocomposites thin film by solid-state reaction method and investigated its structural and magnetic properties. Recently, Co-In 2 O 3 nanocomposites and cobalt-doped In 2 O 3 have attracted significant attention due to their applications in optoelectronic, spintronic devices and gas sensors [58].…”