Layered Structure Oxides for Fatigue Free Ferroelectric Applications

Abstract

ABSTRACTSrBi2(TaxNb1−x)2O9 (SBTN) layered structure oxides have been investigated for possible fatigue free ferroelectric thin film applications. High quality stoichiometric thin films of these oxides have been fabricated, across the solid solution range, using the technique of pulsed laser ablation SBTN thin films with a composition close to x=0.4 showed excellent ferroelectric properties and no fatigue up to 1010 switching cycles. Typically, these films showed a 2Pr value of 22 μC/cm2, an Ec of 60 kV/cm and a resistivity close to 5 × 1012 Ω-cm. The ferroelectric properties of these films were found to depend on the orientation. Predominantly c-axis oriented films have been fabricated on MgO (100)/Pt (100) substrates. By comparison, the c-axis oriented films were found to exhibit similar Pr values but significantly lower Ec values (by 15 kV/cm) and a higher resistivity. The fatigue free behavior of these layered structure oxides has been ascribed to the absence of any volatile species in their sublattice exhibiting polarization (i.e., the perovskite-like units in the layered structure).