Fast time-resolved x-ray diffraction in BaTiO3 films subjected to a strong high-frequency electric field

The pulsed synchrotron radiation from the Advanced Photon Source of Argonne National Laboratory was used to measure the dynamic structural response in 200-nm-thick BaTiO3 ferroelectric films, in situ, under the application of a high-frequency electric field. X-ray diffraction measurements were performed in the stroboscopic mode, i.e., by synchronizing the x-ray bursts with the electric-field periodicity. Time-dependent variations of lattice parameters were derived from the electric-field-induced distortions of the diffraction profiles. Drastic reduction of the relaxation time, from 6.9 ns at 71.69 MHz down to 0.7 ns at 521.36 MHz, was found with an increase of the electric-field frequency. (C) 2002 American Institute of Physics.