  Coherent precipitation of ordered phases is responsible for providing
exceptional high temperature mechanical properties in a wide range of
compositionally complex alloys (CCAs). Ordered phases are also essential to
enhance the magnetic or catalytic properties of alloyed nanoparticles. The
present work aims at demonstrating the relevance of Bragg coherent diffraction
imaging (BCDI) to study bulk and thin film samples or isolated nanoparticles
containing coherent nanoprecipitates / ordered phases. Crystals of a few tens
of nanometres are modelled with realistic interatomic potentials and relaxed
after introduction of coherent ordered nanoprecipitates. Diffraction patterns
from fundamental and superstructure reflections are calculated in the kinematic
approximation and used as input to retrieve the strain fields using algorithmic
inversion. We first tackle the case of single nanoprecipitates and show that
the strain field distribution from the ordered phase is retrieved very
accurately. Then, we investigate the influence of the order parameter S on the
strain field retrieved from the superstructure reflections and evidence that a
very accurate strain distribution can be retrieved for partially ordered phases
with large and inhomogeneous strains. In a subsequent section, we evaluate the
relevance of BCDI for the study of systems containing many precipitates and
demonstrate that the technique is relevant for such systems. Finally, we
discuss the experimental feasibility of using BCDI to image ordered phases, in
the light of the new possibilities offered by the 4 th generation synchrotron
sources.
