Characterizing compositional heterogeneity involves a combination of techniques. Spectroscopic methods such as X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) can provide information about the surface composition. Microscopic techniques like scanning electron microscopy (SEM) and transmission electron microscopy (TEM) can reveal the distribution of different phases and elements at the nanoscale. Additionally, X-ray diffraction (XRD) can be used to identify crystalline phases, while mass spectrometry can offer insights into the elemental composition.
