We apply ultrafast X-ray diffraction with femtosecond temporal resolution to
monitor the lattice dynamics in a thin film of multiferroic BiFeO$_3$ after
above-bandgap photoexcitation. The sound-velocity limited evolution of the
observed lattice strains indicates a quasi-instantaneous photoinduced stress
which decays on a nanosecond time scale. This stress exhibits an inhomogeneous
spatial profile evidenced by the broadening of the Bragg peak. These new data
require substantial modification of existing models of photogenerated stresses
in BiFeO$_3$: the relevant excited charge carriers must remain localized to be
consistent with the data

Adamo, C.

Bargheer, M.

Chen, P.

Evans, P. G.

Gaal, P.

Herzog, M.

Li, Y.

Schick, D.

Schlom, D. G.

Wen, H.

English

arXiv

We apply ultrafast x-ray diffraction with femtosecond temporal resolution to monitor the lattice dynamics in a thin film of multiferroic BiFeO3 after above-band-gap photoexcitation. The sound-velocity limited evolution of the observed lattice strains indicates a quasi-instantaneous photoinduced stress which decays on a nanosecond time scale. This stress exhibits an inhomogeneous spatial profile evidenced by the broadening of the Bragg peak. These new data require substantial modification of existing models of photogenerated stresses in BiFeO3: the relevant excited charge carriers must remain localized to be consistent with the data

Schlom, D.

Evans, P.

MPG.PuRe