Ultrafast charge relocation in an ionic crystal probed by femtosecond x-ray powder diffraction
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
a e-mail: email@example.com
Transient electron density maps of potassium dihydrogen phosphate(KH2PO4, KDP) are derived from femtosecond x-ray powder diffraction patterns. Upon photoexcitation, the low-frequency TO soft mode is elongated impulsively and modulates the electronic charge distribution on the length scale of interatomic distances, much larger than the vibrational amplitude of the nuclear motion. The results demonstrate a charge transfer from the volumes around the P-atoms to those containing the O—H···O units and a quadrupolar distortion of the K+ charge distribution. This behavior reflects the interplay of nuclear motions and electric polarizations in the ionic crystal lattice.
© Owned by the authors, published by EDP Sciences, 2013
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.