Retention Characteristics of Five‐Layered Aurivillus Films With Large Polarization

Abstract

The value of 2Pr (twice the polarization at zero electric field) in the five‐layered Aurivillus film Bi6Fe2Ti3O18 is greater than 50 μC cm−2, which is almost an order of magnitude higher than that of the bulk (4 μC cm−2). Moreover, the well‐defined hysteresis loop of this film can persist at the measurement frequency of 100 kHz, indicating the ultra‐fast switching speed of such a domain. The frequency dependence of the coercive field obeys a power‐law form, Ectrue(ftrue)=bold-italicsfbold-italicd/bold-italicα, indicating that its domain switching kinetics are influenced by the motion of the domain wall. The polarization of the Bi6Fe2Ti3O18 thin film remains essentially constant at a waiting time of up to 2 × 104 s, and is independent of the applied electric field. The switchable polarization loss is 32% after 9 × 1010 read/write switching cycles at a frequency of 1 MHz. This change in the switchable polarization is discussed in terms of the aggregation of oxygen vacancies in the film.