Growth morphology study of cathodically electrodeposited Fe3O4 thin films at elevated temperatures

We investigated the electrodeposition of Fe3O4 thin films in the Fe3+-triethanolamine system by galvanostatic deposition at elevated temperatures. It was found that with a fixed current density, the concentration of Fe3+ ions had a significant impact on the electrodeposition rate, while the deposition temperature and time strongly affected the morphology of the Fe3O4 thin films. Fe3O4 thin films deposited in electrolyte with high Fe3+ concentration and at high temperature (>80 °C) exhibited a dense and uniform morphology and were composed of globular or polyhedral crystallites, while the Fe3O4 thin films deposited at low temperatures (<70 °C) were loose and flake-like. Based on the empirical observations, a hypothetical growth model for the electrodeposition of Fe3O4 at elevated temperatures was proposed.