This Thesis provides a comprehensive and correlative investigation of the microstructure, chemical state, and electrochemical reactivity of manganese oxide (MnO_x) films, aiming to gain a deeper understanding of the deposition and dissolution mechanism of MnO_x films.
Two distinct methods were employed for preparing MnO_x films: anodic electrodeposition from Mn²⁺ solution and anodic oxidation of metallic Mn. In the case of anodic electrodeposition, an extensive inspection of the as-deposited MnO_x films was conducted using a combination of Scanning Electron Microscopy, Transmission Electron Microscopy cross-sectional analysis, Raman Spectroscopy, Rutherford Backscattering Spectrometry, Elastic Recoil Detection Analysis, and X-ray Photoelectron Spectroscopy characterization techniques. The findings revealed that the electrodeposited precursor film consists of nanocrystals of α-Mn₃O₄ dispersed in an amorphous MnOOH matrix phase under de-aerated electrolyte conditions. In contrast, the Electrochemical Quartz Crystal Microbalance setup allowed for the identification of Mn₃O₄ and Mn₂O₃ phases formation in an aerated electrolyte.
[...]