X-ray Imaging Studies of Domain Dynamics in Ferroelectrics by in- situ Electric-field Poling Studies

Periodically-poled crystals, into which arrays of “up” and “down ” inversion (180º) domains are deliberately introduced, have been of interest in nonlinear optics for a number of years. However, such deliberately-designed arrays of domains also present ideal systems for study in the field of domain dynamics as they are a very close approximation in reality to the starting point for theoretical models of domain contributions to the dielectric susceptibility and promise much insight into the behaviour of ferroelectrics in general. In recent years, we have demonstrated[1,2] that the equilibrium atomic level structure of ferroelectric inversion domains can be determined for periodically-poled crystals when they are illuminated by highly laterally-coherent x-rays at beamline ID19 of the ESRF. Under these conditions