Zinc Oxide (ZnO) exhibits a plethora of physical properties potentially advantageous in
many roles and is why it one of the most studied semiconductor compounds. When doped
or in its intrinsic state ZnO demonstrates a multitude of electronic, optical and magnetic
properties in a large variety of manufacturable morphologies. Thus it is inherently important
to understand why these properties arise and the impact potentially invasive sample
preparation methods have for both the function and durability of the material and its
devices.
Coherent X-ray Diff�raction Imaging (CXDI) is a recently established non-destructive technique
which can probe the whole three dimensional structure of small crystalline materials
and has the potential for sub angstrom strain resolution. The iterative methods employed
to overcome the `phase problem' are described fully.
CXDI studies of wurtzite ZnO crystals in the rod morphology with high aspect ratio are
presented. ZnO rods synthesised via Chemical Vapour Transport Deposition were studied
in post growth state and during in-situ modifi�cation via metal evaporation processing and
annealing. Small variations in post growth state were observed, the physical origin of
which remains unidentifi�ed. The doping of a ZnO crystal with Iron, Nickel and Cobalt
by thermal evaporation and subsequent annealing was studied. The evolution of diff�using
ions into the crystal lattice from was not observed, decomposition was found to be the
dominant process.
Improvements in experimental technique allowed multiple Bragg reflections from a single ZnO crystal to be measured for the fi�rst time. Large aspect ratio ZnO rods were used to
probe the coherence properties of the incident beam. The longitudinal coherence function
of the illuminating radiation was mapped using the visibility of the interference pattern
at each bragg reflection and an accurate estimate of the longitudinal coherence length
obtained, \xi(L) = 0.66\pm 0.02 \mu m. The consequences for data analysis are discussed. The
combination of multiple Bragg reflections to realise three dimensional displacement �fields
was also approached