Application of X-ray spectroscopy to the study of electrochemically formed surface oxide films

Many analytical techniques can provide information regarding the chemical state, structure, and properties of materials. This paper focuses on two; X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS), and their application to the study of electrochemically formed oxide films. A brief review of the phenomena underlying these techniques is provided, along with a description of the commonly used means for implementing them. Their capabilities and limitations are discussed, with an emphasis on the study of passive film composition and oxidation state. A summary of the behavior of Cr in oxide films on Al-Cr alloys is presented as an example. The coordinated use of both XPS and XAS is shown to be useful in achieving full understanding of materials systems such as electrochemically formed oxide films.