Ferroelectric Bilayer Film Research Articles

Dynamic Pyroelectric Properties of a Ferroelectric Bilayer Film

Making use of the Landau-Khalatnikov equation of motion, the dynamic pyroelectric properties in a ferroelectric bilayer film with a surface transition layer and ferroelectric coupling have been investigated for the first time. We mainly study the pyroelectric properties of the bilayer film response to a pulsed electric field. The results indicate that the pyroelectric coefficient as a function of the pulsed electric field depends strongly on the ferroelectric coupling, surface transition layer, frequency of the pulsed electric field, and temperature.

Piezoelectric and dielectric properties ofPb(Zr,Ti)O3ferroelectric bilayers

The dielectric and piezoelectric properties of an epitaxial $\mathrm{PbZ}{\mathrm{r}}_{0.8}\mathrm{T}{\mathrm{i}}_{0.2}{\mathrm{O}}_{3}/\mathrm{PbZ}{\mathrm{r}}_{0.6}\mathrm{T}{\mathrm{i}}_{0.4}{\mathrm{O}}_{3}$ ferroelectric bilayer film were studied. Time-resolved synchrotron x-ray microdiffraction provided access to layer-specific structural information during electric-field-induced changes. The observed dielectric and electromechanical responses are consistent with a weak electrostatic polarization coupling and can be described using a thermodynamic model of epitaxial ferroelectric bilayers. The weak electrostatic coupling between ferroelectric layers can enable unusual tail-to-tail and head-to-head polarization configurations. X-ray measurements of the piezoelectric response of the ferroelectric bilayer at a microsecond time scale confirmed a possible tail-to-tail polarization domain configuration.

Switching dynamic behavior of a ferroelectric bilayer film

Based on the Landau-Khalatnikov equation of motion, the switching dynamic behaviors, (including the average polarization, switching time, switching current and coercive field) of a ferroelectric bilayer film with a surface transition layer within each constituent thin film and a ferroelectric interfacial coupling between two thin films have been investigated. Results reveal that there is a competitive mechanism in the bilayer film, the action of surface transition layer and the interfacial coupling. The abnormal behavior is discovered in the polarization reversal process of the bilayer film, which can be attributed to the competition between the surface transition layer and the interfacial coupling. The combined action of surface transition layer and interfacial coupling plays a decisive role on the dynamic properties of a ferroelectric bilayer film.

Abnormal dynamic behavior in a ferroelectric bilayer film

Based on the Landau–Khalatnikov equation of motion, the switching dynamic behavior (including switching time, hysteresis loop and remanent polarization) of a ferroelectric bilayer film with surface transition layer within each constituent thin film and an interfacial coupling between two thin films has been first studied. The results show that the serious lag phenomenon of the hysteresis loop of the bilayer film occurs due to the strong strength of the interfacial coupling. It is interesting to note that there is a critical point, which is an equilibrium point of two contrary actions of the surface transition layer and interfacial coupling. The abnormal behavior of the switching time and remanent polarization in the bilayer film is attributed to the competition of the surface transition layer and interfacial coupling.

Size Effects of the Properties in a Ferroelectric Bilayer Film with Surface Transition Layers

Using the transverse Ising model theory, a ferroelectric bilayer film, considering the surface transition layer within each constituent slab and an interfacial coupling between two slabs, is investigated in the framework of the mean-field approximation. We discuss in detail the thickness effects of the spontaneous polarization and dielectric susceptibility of a ferroelectric bilayer film under two conditions of interfacial coupling: ferroelectric and antiferroelectric coupling. The results show some unexpected phenomena for a small thickness of a ferroelectric bilayer film.

Dielectric susceptibility of a ferroelectric bilayer film with surface transition layers

Using the transverse Ising model within the framework of the mean-field theory, we investigate a ferroelectric bilayer film with the surface transition layer within each constituent slab and an antiferroelectric interfacial coupling between two slabs. The combined influence of the surface transition layer and antiferroelectric interfacial coupling on the dielectric susceptibility of a bilayer film is discussed in detail. The results show that the surface transition layer plays a crucial role in dielectric susceptibility of a bilayer film.

Influence of the surface transition layers on the pyroelectric properties of a ferroelectric bilayer film

Based on the transverse Ising model within the framework of the mean-field approximation, a ferroelectric bilayer film composed of two different slabs, with the surface transition layer within each constituent slab and a ferroelectric interfacial coupling between two slabs, is investigated. The influence of the surface transition layer on the pyroelectric properties of a bilayer film is discussed in detail. The results show that the pyroelectric properties of a bilayer film embody show some interesting phenomena on account of the presence of surface transition layer.

The polarization and dielectric susceptibility of a ferroelectric bilayer film

A ferroelectric bilayer film consisting of two different ferroelectric constituent films with a transition layer within each constituent film and interfacial coupling between two materials is investigated based on the Ginzburg–Landau–Devonshire phenomenological theory. A parameter α, which describing the differences between physical properties of two constituent films is first introduced in our paper, and reflects a more realistic situation compared to the previous treatments assuming the same two constituent films. We study the polarization and dielectric susceptibility properties of the ferroelectric bilayer film with two different constituent films. The results present some interesting phenomena due to the introduction of parameter α.

The hysteresis loops of a ferroelectric bilayer film with surface transition layers

Based on the transverse Ising model in the framework of the mean field approximation, this paper discusses a ferroelectric bilayer film with the surface transition layers within each constituent slab and an antiferroelectric interfacial coupling between two slabs. The hysteresis loop of a bilayer film is investigated. The results show that the surface transition layer in a ferroelectric bilayer film plays a significant role in realizing the multiple-state memory.

Theoretical study on the mechanism of abnormal dielectric susceptibility behaviors of ferroelectric bilayer films

Based on the modified Ginzburg–Landau–Devonshire phenomenological theory, a ferroelectric bilayer film with the transition layer within each constituent film and an interfacial coupling between two materials has been studied. The dielectric susceptibility of a bilayer film composed of two equally thick ferroelectric constituent films is discussed. The results show that there is a transition point, which is an equilibrium point of two contrary actions of the transition layer and interfacial coupling. The anomalous dielectric susceptibility behaviors of a ferroelectric bilayer film are ascribed to the competition of the transition layer and interfacial coupling deviated from this transition point.

Combined effect of the transition layer and interfacial coupling on the properties of ferroelectric bilayer film

Within the framework of modified Ginzburg–Landau–Devonshire phenomenological theory, a ferroelectric bilayer film with a transition layer within each constituent film and an interfacial coupling between two materials has been studied. Properties including the Curie temperature and the spontaneous polarization of a bilayer film composed of two equally thick ferroelectric constituent films are discussed. The results show that the combined effect of the transition layer and the interfacial coupling plays an important role in explaining the interesting behaviour of ferroelectric multilayer structures consisting of two ferroelectric materials.