相关论文: Thermodynamic theory of epitaxial ferroelectric th…
A thermodynamic theory is developed for dense laminar domain structures in epitaxial ferrolectric films. It is found that, at some critical misfit strain between the film and substrate, the 90 degrees c/a/c/a domain structure becomes…
We develop a phenomenological thermodynamic theory of ferroelectric BaTiO3 (BT) thin films epitaxially grown on cubic substrates using the Landau-Devonshire eight-order potential. The constructed "misfit-temperature" phase diagram is…
The mean-field Landau-type theory is used to analyze the polarization properties of epitaxial ferroelectric thin films grown on dissimilar cubic substrates, which induce biaxial compressive stress in the film plane. The intrinsic effect of…
Ferroelectric thin films under epitaxial strain exhibit a variety of vortex-like topological polarization textures. To analyze them, we build on the Ginzburg-Landau-Devonshire framework and extend the previously introduced soft-domain…
Ferroelectric and dielectric properties of polydomain (twinned) single-crystal Pb(Zr1-xTix)O3 thin films are described with the aid of a nonlinear thermodynamic theory, which has been developed recently for epitaxial ferroelectric films…
A phenomenological thermodynamic theory of BaxSr(1-x)TiO3 (BST-x) thin films epitaxially grown on cubic substrates is developed using the Landau-Devonshire approach. The eighth-order thermodynamic potential for BT single crystal and…
An analytical theory is developed for predicting the nonlinear susceptibility of ionic polarization to continuous electromagnetic waves in both bulk and strained thin film ferroelectrics. Using a perturbation method for solving the…
We studied the phase diagram of thin ferroelectric films with incommensurate phases and semiconductor properties within the framework of Landau-Ginzburg-Devonshire theory. We performed both analytical calculations and phase-field modelling…
Thermodynamic theory is developed for the ferroelectric phase transition of an ultrathin film in equilibrium with a chemical environment that supplies ionic species to compensate its surface. Equations of state and free energy expressions…
Currently used methods for the description of thermodynamics of ferroelectric thin films (Landau theory or ab initio based Monte-Carlo simulations) are based on an energy expansion in terms of internal degrees of freedom. It was shown that…
In the framework of Landau--Ginzburg--Devonshire (LGD) phenomenological theory, the influence of misfit strains, surface energy, and finite-size effects on phase diagrams, polar properties, and hysteresis loops has been calculated for…
We present molecular dynamics simulations of a realistic model of an ultrathin film of BaTiO$_3$ sandwiched between short-circuited electrodes to determine and understand effects of film thickness, epitaxial strain and the nature of…
Heterostructures consisting of PbZr0.2Ti0.8O3 and PbZr0.4Ti0.6O3 films grown on a SrTiO3 (100) substrate with a SrRuO3 bottom electrode were prepared by pulsed laser deposition. Using the additional interface provided by the ferroelectric…
Ferroelectric BaTiO3 films with large polarization have been integrated with Si(001) by pulsed laser deposition. High quality c-oriented epitaxial films are obtained in a substrate temperature range of about 300 deg C wide. The deposition…
A thermodynamic theory of ferroelectric thin film multilayers is developed. The free energy function is written down using a multilayer model in which c-domain layers of one ferroelectric material alternate with a-domain layers of a second…
Ferroelectric films usually have phase states and physical properties very different from those of bulk ferroelectrics. Here we propose free-standing ferroelectric-elastic multilayers as a bridge between these two material systems. Using a…
The structural evolution of a polydomain ferroelectric Pb(Zr0.2Ti0.8)O3 film was studied by temperature dependent X-ray diffraction. Two critical temperatures were evidenced: T*=740K, corresponding to a change in the domain structure…
The structural evolution of epitaxial mono-oriented (i.e. with the c-axis perpendicular to the interface) ferroelectric Pb(Zr0.2,Ti0.8)O3 thin film has been investigated, using high resolution, temperature dependent, X-ray diffraction. The…
The Landau theory of 180 degrees domain walls in BaTiO3 type ferroelectric particles is presented. Results of exact description of domain walls in bulk enabled us to formulate variational approach to theory of domain walls in corresponding…
Recent works have shown that the domain walls of room-temperature multiferroic BiFeO3 (BFO) thin films can display distinct and promising functionalities. It is thus important to understand the mechanisms underlying domain formation in…