2, University College London, London, , United Kingdom
Bragg Coherent Diffractive Imaging (BCDI) uses coherent X-ray beams for imaging the structure and dynamics of nanocrystals. While BCDI continues to develop at current and future new high brightness X-ray facilities, it is also adding new directions, such as reaching wavelength-limited resolution, higher energies and in-situ buried configurations of nanocrystals. In this talk I will address the potential application of BCDI to the problem of imaging domain structures. Domain structures occur widely in crystals which show superstructure ordering, such as ferroelastic domains in ferroelectric materials, or charge ordered domains in charge-density-wave (CDW) systems. When such a sample is measured with coherent X-rays, the broad superstructure peak becomes speckled because of interference between the domains. I will illustrate the phase domain problem with the example of a nano-sized bicrystal of Barium Titanate. The two domains each generate a BCDI pattern, but where these overlap in reciprocal space, additional speckles are generated which report the relative positions of the two halves of the bicrystal.