I performed XPS depth profiling to investigate surface chemistry and compositional gradients through thin films. Controlled sputtering and peak fitting enabled evaluation of oxidation states and chemical uniformity. This analysis provided insight into surface and near-surface stability after processing 

I used XPS to analyze surface chemistry following electrochemical corrosion testing. XPS measurements revealed oxidation and passivation behavior of alloy surfaces exposed to corrosive environments. These results complemented electrochemical data and supported interpretation of corrosion mechanisms.