Ferroelectric and dielectric behavior of heterolayered PZT thin films

Abstract

Heterolayered Pb(Zr1−xTix)O3 thin films consisting of different numbers of alternating Pb(Zr0.7Ti0.3)O3 and Pb(Zr0.3Ti0.7)O3 layers are studied. They exhibit (001)∕(100) preferred orientation and dense microstructure when baked at 500°C and then thermally annealed at 650°C. They demonstrate a considerably low leakage current density in the order of 10−7A∕cm2. Their ferroelectric and dielectric properties are improved with increasing number of alternating Pb(Zr0.7Ti0.3)O3 and Pb(Zr0.3Ti0.7)O3 layers, thereby the six-heterolayered PZT thin film shows a much enhanced remanent polarization of 41.3μC∕cm2 and relative permittivity of 710 at 1kHz. In fatigue test, a wake-up phenomenon is observed with the heterolayered films, where the degradation in switchable polarization is delayed. At elevated temperatures, the wake-up phenomenon was reduced, leading to fatigue degradation at a relatively lower number of switching cycles. The phenomenon is related to the injected electron causing oxygen vacancies, the accumulation of which impedes the domain switching.

Labile Ferroelastic Nanodomains in Bilayered Ferroelectric Thin Films

“…Cross-sectional electron microscopy and electron-probe microanalysis confirmed that there was no intermixing between the functional layers. Further processing details and macroscopic ferroelectric properties are given elsewhere [35]. A multimode atomic force microscope with Pt/Ir-coated cantilever (with typical tip radius 7 nm, force constant 0.2 N m À1 , resonant frequency 13 kHz) was employed at a scan rate of 0.8 Hz for the visualization of domain structure.…”

Electrical measurements of dielectric nonlinearities in ferroelectric bilayer thin films

“…1-3 These properties find their applications in microelectromechanical systems, electronic memories, sensors, and actuators. [4][5][6] Significant attention is being paid to engineering ferroelectric systems with enhanced dielectric properties via graded ferroelectric films, complex oxide superlattices, and ferroelectric multilayers. 7-10 A simple and reliable approach to measuring dielectric properties in ferroelectric systems including ferroelectric multilayers is important for the development of new materials.…”

Domain-reorientation-induced polarization wake-up of PbTiO3 based ferroelectric thin films

“…x O 3 compounds but also in the HfO 2 based ferroelectric thin films and so on [19][20][21][22][23][24]. The physical origins of wake-up effect is associated with the domain reorientation and the defect deformation.…”