Improvement of ferroelectric fatigue endurance in multiferroic (Ba₀.₅Sr₀.₅)TiO₃/(Bi₁.₀₅La₀.₀₅)FeO₃/(Ba₀.₅Sr₀.₅)TiO₃ sandwich structures

Abstract

We report the improved ferroelectric properties in dielectric/multiferroic/dielectric sandwich structures composed of Ba₀.₅Sr₀.₅TiO₃(BST) and Bi₁.₀₅La₀.₀₅FeO₃ (BLF). Compared with the single BLF film, the trilayer structures exhibit a lower dielectric loss and weaker frequency dependence of dielectric properties. At room temperature, the remnant polarization and saturation polarization of the trilayer structures are 34.3 and 46.9 μC/cm², respectively. More interestingly, the polarization of BST/BLF/BST trilayer exhibits a fatigue-free characteristic of up to 10⁹ switching cycles. Applying Dawber’s model, the concentration of oxygen vacancies and barrier energy of oxygen vacancies migration in BST/BLF/BST trilayer are calculated as 6.1×10¹⁷ cm⁻³ and 1.33 eV, respectively.