The study of the local atomic structure by means of X-ray photoelectron diffraction

Photoelectron diffraction is under rapid development to a powerful method for the investigation of structures at surfaces. Within the escape length of photoelectrons an element-specific signal can be chosen from the photoelectron spectrum in order to separately investigate the local structure around a certain element, or in high-resolution mode, the local structure around a specific chemical state. A brief overview of the theoretical and numerical aspects on calculating X-ray photoelectron diffraction intensities is given. The experimental two branches of recording photoelectron diffraction patterns as a function of angle or energy are discussed. Presently, these branches merge due to the availability of tunable high-flux X-ray radiation from third generation synchrotron sources. Examples for structures at surfaces and buried interfaces are discussed. Spin-dependent scattering and diffraction processes within the surface layer may lead to spin-depending intensities observed at the detector. This opens a possible way to investigate magnetic buried structures.