Ferroelectric properties and polarization fatigue of Bi-modified Pb(Zr,Ti)O-3 thin film

Since many industrial applications of ferroelectric lead zirconium titanate [Pb(Zr,Ti)O-3;PZT] thin films are limited due to the problem of degradatio n, in this paper, it was investigated ferroelectric fatigue properties of B i-modified PZT, (Pb1-3/2xBix)(Zr0.52Ti0.48)O-3 (PBZT), and PBZT/PZT/PBZT th in films deposited onto platinized silicon wafers by means of sol-gel metho d. Ferroelectricity, confirmed by P-E hysteresis characteristics, was found below x=0.25 in both films. It was shown that the formation of Bi-modified structure be independent of Bi content, although the Bi content strongly a ffect P-r and E-c. The values of both dielectric constant and remnant polar ization decrease monotonically with increasing the Bi contents, but the rat e of polarization fatigue slightly increases. However, both films show good crystallinity and well saturated hysteresis curve at x=0.05, which is rela ted to the rate slope of polarization fatigue. This paper describes how the presence of Bi affects the fatigue characteristics of PBZT thin films. Fat igue behavior of PBZT/PZT/PBZT multilayer was improved as compared to that of PBZT thin film.