Ultrafast Photostriction In Thin Film Bismuth Ferrite And Its Correlation To Electronic Dynamics

A series of laser pump, x-ray probe experiments show that above band gap photoexcitation can generate a large out-of-plane strain in multiferroic BiFeO3 thin films. The strain decays in a time scale that is the same as the photo-induced carriers measured in an optical transient absorption spectroscopy experiment. We attribute the strain to the piezoelectric effect due to screening of the depolarization field by laser induced carriers. A strong film thickness dependence of strain and carrier relaxation is also observed, revealing the role of the carrier transport in determining the structural and carrier dynamics in complex oxide thin films. © 2013 Materials Research Society.15282530Catlan, G., Scott, J.F., (2009) Advanced Mat, 21, p. 2463Wang, J., (2003) Science, 299, p. 1719Zhao, T., (2006) Nat Mat, 5, p. 823Lebeugle, D., (2008) Phys. Rev. Lett., 100, p. 227602Nakashima, S., (2009) J. Appl. Phys., 105, p. 061617Wen, H., Phys. Rev. Lett., , in pressKundys, B., (2010) Nat. Mat., 9, p. 803Daranciang, D., (2012) Phys. Rev. Lett., 108, p. 087601Tefft, W.E., (1967) Phys. Rev., 164, p. 1032Sasamoto, S., (2009) J. Appl. Phys., 105, p. 083102Vasiliu-Doloc, L., (1999) Phys. Rev. Lett., 83, p. 4393Fiorentini, V., (1999) Phys. Rev. B, 60, p. 884