Linearized augmented plane wave (LAPW) calculations are performed for periodic (001) and (111) slabs of BaTiO3 to understand the effects of surfaces on ferroelectric BaTiO3. The (111) slab is found to be much less stable than the (001) slab. The average surface energies are respectively 3700 erg/cm and 1600 erg/cm. The depolarization field is sufficiently large in the ideal unrelaxated slab to ...

We have investigated the role of the Ti-O Coulomb repulsions in the appearance of the ferroelectric state in BaTiO3 as well as the role of the Zn-O Coulomb repulsions in BiZn0.5Ti0.5O3, using a first-principles calculation with optimized structures. In tetragonal BaTiO3, it is found that the Coulomb repulsions between Ti 3s and 3p states and O 2s and 2p states have an important role for the app...

Multiferroic materials exhibit magnetoelectric (ME) coupling and promise new device applications including magnetic sensors, generators, and filters. An effective method for developing ME materials with enhanced ME effect is achieved by the coupling through the interfacial strain between piezoelectric and magnetostrictive materials. In this study, the electrical and magnetic properties of Ga do...

The atomic-scale response of dielectrics/ferroelectrics to electric fields is central to their functionality. Here we introduce an in situ characterization method that reveals changes in the local atomic structure in polycrystalline materials under fields. The method employs atomic pair distribution functions (PDFs), determined from X-ray total scattering that depends on orientation relative to...

The collective dipole behaviors in (BaTiO3)m/(SrTiO3)n composite nanowires are investigated based on the first-principles-derived simulations. It demonstrates that such nanowire systems exhibit intriguing dipole orders, due to the combining effect of the anisotropic electrostatic interaction of the nanowire, the SrTiO3-layer-modified electrostatic interaction and the multiphase ground state of ...

In this letter, we examine the potential of a functional device that can have good transistor and stress sensor properties. The device examined is based on the use of a thin oxide with high piezoelectric coefficients under the gate region. Channel charge and current are controlled by gate voltage or by stress. We examine the performance of two classes of heterostructures that are important semi...

Thermally-induced loss of piezoelectricity in ferroelectric Na0.5Bi0.5TiO3–BaTiO3 Report Title The loss of piezoelectricity in ferroelectric sodium bismuth titanate (NBT) in solid solution with barium titanate ((1? x)NBT?xBT) is studied by means of thermal depoling and Raman spectroscopy. In the range 0?x?13%, the highest thermal stability of the piezoelectric coefficients is found in x=13%, fo...

We present a study of the control electric field induced strain on magnetic and electrical transport properties in magneto-elastically coupled artificial multiferroic Fe3O4/BaTiO3 heterostructure. In this heterostructure, Fe3O4 thin film is epitaxially grown form bilateral domains, analogous to a-c stripe domains underlying BaTiO3(001) substrate. By in-situ dependent magnetization measurements,...