“…Currently, numbers of lead-containing ferroelectric materials, such as Pb(Zr,Ti)O 3 (PZT), (Pb,Ba)ZrTiO 3 (PBZ) and (Pb,Ba)(Zr,Nb)O 3 (PBZN), have achieved significant dielectric tunability and the value of figure of merit (FOM), due to their superior dielectric performance and nonlinear dependence of the dielectric constant upon the applied field [1,2]. However, considering the toxicity of lead, many countries setup environmental regulations to restrict the usage of lead in electronic devices.…”