Charge separation and directed migration of photoelectrons in LiNbO3:Fe crystals after excitation by nanosecond laser pulses

Under nanosecond laser excitation, time-delayed changes in the x-ray diffraction parameters of LiNbO${}_{3}$ and LiNbO${}_{3}$:Fe crystals are revealed. On-tip synchronization of 4-ns optical laser pulses with electron bunches in a synchrotron provides a subnanosecond time resolution for diffraction rocking curve (DRC) dynamics. The crystals exhibit a reversible center-of-mass shift and a decrease in DRC integral intensity with recovery in approximately 35 ns. This behavior indicates the formation and decay of a charged layer due to photoelectron migration.