X-ray standing-wave spectroscopy: A powerful method for probing buried interfaces

In this chapter we present a non-destructive method for characterizing buried interfaces with high depth resolution combining X-rays standing wave and photoemission electron spectroscopy. This method incorporates the power of the X-rays photoelectron spectroscopy, which is a surface sensitive technique in the nanometer and sub-nanometer regime, with the depth selectivity of X-ray standing wave. This method has been successfully applied to study solid/solid interfaces and, more recently, solid/gas and solid/liquid interfaces, as we demonstrate on several examples. In addition, we also describe a few examples of liquid/solid interface characterization by standing wave X-ray fluorescence relevant for catalysis, energy science and biomedical applications.