Fabrication of (Pb_0.9Sr_0.1)TiO₃/SrTiO₃ artificial superlattice thin films and their electromechanical response

Abstract

Artificial superlattice thin films of (Pb_0.9Sr_0.1)TiO₃ (PST)_n/SrTiO₃ (STO)_m were grown on SrRuO₃-electroded DyScO₃ (001)_pc substrates by pulsed laser deposition. X-ray diffraction (XRD) showed that the fabricated superlattice thin films have a good periodicity in the out-of-plane direction, indicating the sharp interfaces regardless of the difference in layer thickness. Synchrotron XRD indicated that the film with n/m = 14/20 had a weak periodicity in the in-plane direction, which may had arisen from the ordered polar vortex arrays existing in the PST layers. All the fabricated superlattice thin films showed the electric field-induced strain, though its magnitude was smaller than that for typical ferroelectric materials.