PHOTOELECTRON DIFFRACTION - NEW DIMENSIONS IN-SPACE, TIME, AND SPIN

The current status of photoelectron diffraction studies of surface str uctures is briefly reviewed, and several recent developments and propo sals for future areas of application are then discussed. The applicati on of full-solid-angle diffraction data, together with simultaneous ch aracterization by low energy electron diffraction and scanning tunneli ng microscopy, to epitaxial growth is first considered. New instrument ation for carrying out such studies with third-generation synchrotron radiation is then presented and several types of results obtained with it are discussed. These results include photoelectron diffraction fro m surface and interface atoms, the possibility of time-resolved measur ements, and circular dichroism in photoelectron angular distributions, The addition of spin to the photoelectron diffraction measurement is also considered, and can be achieved either through core-level multipl et splittings or by circular-polarized excitation of spin-orbit-split levels. This last development makes it possible to study short-range m agnetic order, perhaps even in a holographic fashion.