Switching behaviour of modulated ferroelectrics: the kinetics of the field induced lock-in transition in K2SeO4

The field induced switching process across the ferroelectric lock-in transition in K2SeO4 has been studied on a millisecond timescale using stroboscopic neutron diffraction. The time evolution of both the first and the third order satellites was examined. The time constants are found to vary with temperature between 0.2 and 1.2 ms. This is an order of magnitude faster than in the isostructural Rb2ZnCl4. Moreover, the time dependence of the satellite's linewidth provides information about the evolution of the coherence of the modulated structure.