Effects of Bi doping on dielectric and ferroelectric properties of PLBZT ferroelectric thin films synthesized by sol–gel processing

Abstract

[Pb 0·95(La1 − y Bi y ) 0·05][Zr0·53Ti0·47]O3 (PLBZT) ferroelectric thin films have been synthesized on indium tin oxide (ITO)-coated glass by sol–gel processing. PLBZT thin films were annealed at a relatively low temperature of 550 °C in oxygen ambient. Effects of Bi doping on structure, dielectric and ferroelectric properties of PLBZT were investigated. Bi doping is useful in crystallization of PLBZT films and promoting grain growth. When the Bi-doping content \({\mathit{y}}\) is not more than 0·4, an obvious improvement in dielectric properties and leakage current of PLBZT was confirmed. However, when the Bi-doping content is more than 0·6, the pyrochlore phase appears and the remnant polarization P r of PLBZT thin films is smaller than that of \(\left({Pb}_{{1-x}} {\bf La}_{x}\right)\!\!\left({Zr}_{{1-y}} {Ti}_{y}\right){O}_{3}\) (PLZT) thin films without Bi doping. PLBZT thin films with excessive Bi-doping content are easier to fatigue than PLZT thin films.