All-Epitaxial Trilayered Ferroelectric (Bi,La)4Ti3O12/Pb(Zr0.4Ti0.6)O3/(Bi,La)4Ti3O12 Thin Films on SrTiO3 Substrates by Pulsed Laser Deposition

Abstract

Trilayered ferroelectric (Bi,La)4Ti3O12 (BLT)/Pb(Zr,Ti)O3 (PZT)/(Bi,La)4Ti3O12 thin films were grown epitaxially on SrTiO3 (STO) substrates by pulsed laser deposition. The epitaxial relationships between BLT, PZT and STO were identified to be BLT(001)∥PZT(001)∥STO(001) and BLT[110]∥PZT[100]∥STO[100] for the trilayered thin films on (001)-oriented STO substrates, whereas for the trilayered thin films on (011)-oriented STO substrates, the epitaxial relationships were BLT(118)∥PZT(011)∥STO(011) and BLT[110]∥PZT[100]∥STO[100]. The morphology of the BLT/PZT interfaces and of the surface of the trilayered thin films depended largely on the orientation of the film layers. A rather large remanent polarization as well as a high fatigue resistance of up to 1010 switching pulse cycles was obtained for the trilayered thin films deposited on SrRuO3-coated STO substrates.