Structural investigations on optical PLT thin films grown on (100) SrTiO3 by room and high-temperature channeling

Abstract It is well-known that cooling films through the paraelectric/cubic to the ferroelectric/tetragonal phase transition introduces twin structures, because of the coexistence of a- and c-oriented grains. In order to determine relative importance of these defects, we have performed room and high-temperature (450°C) channeling on a lanthanum-doped lead titanate (PLT) sample grown on (100) SrTiO3 (STO). The determined normalized yield minimum based on the Pb signal along the growth direction on this sample is 30% at room temperature. Moreover, the percentage of c-oriented grains, calculated from channeling along [101], is 70%. High-temperaturechanneling shows that the film defects mainly consist of dislocations, and that the defects introduced during growth are more important than those due to the phase transformation.