Photochemical switching of ultrathin PbTiO3 films

The ferroelectric domain ground state of PbTiO3 thin films on Nb:SrTiO3 substrates has been studied as a function of film thickness. High resolution linear Q(x) x-ray diffraction profiles were recorded in order to probe the presence of stripe domains, which were invariably observed for as-grown samples. After photochemical treatment, films thinner than 50 unit cells were switched to a monodomain state that could be reversed upon subsequent annealing. The stripe-domain state is linked to a Q(x) modulation of the Q(z) parameter in the reciprocal space, which disappears upon switching. (c) 2008 American Institute of Physics.