  X-ray photoelectron diffraction (XPD) has developed into a powerful technique
for the structural analysis of solids. Extension of the technique into the
hard-X-ray range (hXPD) gives access to true bulk information. Here we give a
status report on hXPD experiments using a novel full-field imaging technique:
Time-of-flight momentum microscopy (ToF-MM). A special variant of ToF-MM is
capable of recording high kinetic energies (up to >7keV) and enlarged
k-fields-of-view. We present applications that are specific for high kinetic
energies. The strong site specificity of hXPD is exemplified for NbSe2, the
cubic-to-tetragonal transition in SrTiO3 and the zinc-blende structure in
epitaxial GaAs films. Bloch-wave calculations show a very good agreement with
experiment and reveal fingerprint-like signatures of emitter sites in host
lattices. We show a dopant-site analysis in two semiconductors (Mn in GaAs and
Te in Si). Hard-X-ray ARPES plus core-level hXPD enable eliminating the strong
diffraction signature imprinted in HARPES maps.
