Fabrication of Single-Phase Manganese Oxide Films by Metal-Organic Decomposition

Here, single-phase Mn2O3 and Mn3O4 films are successfully fabricated by a facile solution process based on metal-organic decomposition (MOD), for the first time. A formulated manganese 2-ethylhexanoate solution was used as an MOD precursor for the preparation of manganese oxide films. The difference in thermal decomposition behavior of precursor solution in air and inert atmospheres was observed, indicating that the calcination atmosphere is the main factor for controlling the valence of manganese oxide films. Significantly, the solution-coated films on substrates are found to be transformed into single-phase Mn2O3 and Mn3O4 films when they are calcinated under air and inert atmosphere, respectively. The film crystallinity was improved with increasing calcination temperature for both Mn2O3 and Mn3O4 films. In particular, it is noted that the grains of Mn2O3 film were somewhat linearly grown in air, while those of Mn3O4 film exhibited the drastic growth in Ar with an increase of calcination temperature.