SrBi 4Ti 4O 15 thin films of Ti containing bismuth-layered-ferroelectrics prepared by pulsed laser deposition

Abstract

Thin films of SrBi 4Ti 4O 15 (SBTi), a prototype of the Bi-layered-ferroelectric oxide family (Aurivillius phases) with m=4, were fabricated on Pt/TiO 2/SiO 2/Si substrates by pulsed laser deposition (PLD). Structure characterization of the as-grown SBTi thin films by θ–2 θ scan X-ray diffraction (XRD) and scanning electron microscopy (SEM), revealed that the films consisted of (001)- and (100)-oriented crystalline grains. Using Pt/SBTi/Pt/TiO 2/SiO 2/Si configuration, ferroelectric properties of the films were well established with the hysteresis loop of a remnant polarization Pr and a coercive field Ec of 3.11 μC/cm 2 and 68 kV/cm, respectively. The films exhibited excellent fatigue-free characteristics up to 10 11 switching cycles, characteristic of SrBi 2Ta 2O 9 (SBT) and SrBi 2Nb 2O 9 (SBN), and excellent retention characteristics after 10 5 s. The results showed that the Ti containing bismuth-layered-ferroelectrics could also improve the fatigue of the ferroelectric random access memories (FRAMs), and provided an alternative to optimize their ferroelectric properties and processing compatibility.