Solid state synthesis and characterization of ferromagnetic nanocomposite Fe-In2O3 thin films

We have successfully synthesized ferromagnetic Fe-In2O3 nanocomposite thin films for the first time using the thermite reaction Fe2O3 + In = In2O3 + Fe. The initial In/Fe2O3 bilayers were obtained by the deposition of In layers on alpha-Fe2O3 films. The reaction occurs in a self-propagating mode in a homogeneous thermal film plane field at heating rates above 20 K/s and at temperatures above initiation temperature T-in similar to 180 degrees C. At heating rates lower than 20 K/s the mixing of the In and Fe2O3 layers occurs across the whole In/Fe2O3 interface and the synthesis of the ferromagnetic alpha-Fe phase starts above the initiation temperature T-in = 180 degrees C. X-ray diffraction, X-ray photoelectron spectroscopy, Mossbauer spectroscopy, transmission electron microscopy and magnetic measurements were used for phase identification and microstructure observation of the synthesized Fe-In2O3 samples. The reaction products contain (1 1 0) textured alpha-Fe nanocrystals with a diameter around 100 nm and surrounded by an In2O3 matrix. These results enable new efficient low-temperature methods for synthesizing ferromagnetic nanocomposite films containing ferromagnetic nanoclusters embedded in transparent conducting oxides. (C) 2014 Elsevier B.V. All rights reserved.