Thickness Dependence of Dielectric, Leakage, and Ferroelectric Properties of Bi_6Fe_2Ti_3O_(18) Thin Films Derived by Chemical Solution Deposition

摘要

We prepared Bi_6Fe_2Ti_3O_(18) thin films on Pt/Ti/SiO_2/Si substrates with thickness ranging from ～300 to ～900 nm by using a chemical solution deposition route and investigated the thickness effects on the microstructure, dielectric, leakage, and ferroelectric properties of Bi_6Fe_2Ti_3O_(18) thin films. Increasing thickness improves the surface morphology, dielectric, and leakage properties of Bi_6Fe_2Ti_3O_(18) thin films and a well-defined ferroelectric hysteresis loops can form for the thin films with the thickness above 400 nm. Moreover, the thickness dependence of saturation polarization is insignificant, whereas the remnant polarization decreases slightly with increasing thickness and it possesses a maximal value of ～ 20 μC/cm~2 for the 500 nm-thick thin films. The mechanisms of the thickness dependence of micro-structure, dielectric, and ferroelectric properties are discussed in detail. The results will provide a guidance to optimize the ferroelectric properties in Bi_6Fe_2Ti_3O_(18) thin films by chemical solution deposition, which is important to further explore single-phase multiferroics in the n - 5 Aurivillius thin films.