相关论文: Domain wall-grain boundary interactions in polycry…
A common strategy for reducing thermal conductivity of polycrystalline systems is to increase the number of grain boundaries. Indeed, grain boundaries enhance the probability of phonon scattering events, which has been applied to control…
The study of grain size effects in ferroelectric ceramics has attracted great research interest over the last 50 years. Although different theoretical models have been proposed to account for the variation in structure and properties with…
Polar discontinuities and structural changes at oxide interfaces can give rise to a large variety of electronic and ionic phenomena. Related effects have been intensively studied in epitaxial systems, including ferroelectric domain walls…
We report on the experimental investigation of a high-frequency (1MHz - 1.8GHz) dielectric dispersion in unpoled and poled Pb(Zr,Ti)O3 ceramics. Two overlapping loss peaks could be revealed in the dielectric spectrum. The linear dependence…
Engineering of ferroelectric domain structures enables direct control over the switching dynamics and is crucial for tuning the functional properties of ferroelectrics for various applications, ranging from capacitors to future…
Polymer-piezoceramic 0-3 composites combine the flexibility of the polymers and the excellent piezoelectric properties of the ferroelectric based ceramic. While grain size of the ceramic powder is one of the important considerations in the…
Ferroelectrics are widely used for a broad array of technological applications due to their attractive electrical and electromechanical properties. In order to obtain large functional properties, material compositions are often designed to…
Recently we found that when conventional bulk polycrystalline piezoceramics discs (~ 10 mm diameter) are thinned down to thickness ~ 200 microns or below, the measured unipolar electrostrain (UES) values increased phenomenally…
A systematic study of phase separation effects in polycrystalline La_0.5 Ca_0.5 Mn O_3 obtained under different thermal treatments is reported. Samples with average grain size ranging from 200 to 1300 nm were studied. Magnetic and…
Dielectric response e*(f,T) and polar phonon spectra of coarse grain (grain size ~ 4 mkm) and fine grain (grain size ~ 150 nm) ceramics of PbMg_(1/3)Nb_(2/3)O3-35%PbTiO3 were investigated at temperatures 10 - 900 K. e*(f,T) in coarse-grain…
A promising mechanism for achieving colossal dielectric constants is to use insulating internal barrier layers, which typically form during synthesis and then remain in the material. It has recently been shown that insulating domain walls…
Domain walls are of increasing interest in ferroelectrics because of their unique properties and potential applications in future nanoelectronics. However, the thickness of ferroelastic domain walls remains elusive due to the challenges in…
Lead-free Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) ceramics had attracted much attention for the fabrication of microelectronic devices by virtue of their excellent dielectric, ferroelectric and piezoelectric properties. To understand the effects of…
Domain walls are functionally different from the domains they separate, but little is known about their mechanical properties. Using scanning probe microscopy, we have measured the mechanical response of ferroelectric 180o domain walls and…
Bulk polycrystalline piezoelectric ceramics are extensively used in wide ranging applications as actuators, transducers, and sensors. For actuator applications, it is desirable that the piezoelectric ceramic gives as large electric field…
Charge transport across the interfaces in complex oxides attracts a lot of attention because it allows creating novel functionalities useful for device applications. In particular, it has been observed that movable domain walls in epitaxial…
Domain walls in ferroelectrics exhibit a plethora of phases and functionalities not found in the bulk. The interplay of electrostatic, chemical, topological, and distortive inhomogeneities at the walls can be so complex, however, that this…
Dielectric response as a function of frequency for high-permittivity dielectric and ferroelectric materials is discussed emphasizing the dynamic behaviour in the microwave and infrared range. After introducing the usual modelling of the…
The dynamics of dislocation assemblies in deforming crystals indicate the emergence of collective phenomena, intermittent fluctuations and strain avalanches. In polycrystalline materials, the understanding of plastic deformation mechanisms…
The domain size dependence of piezoelectric properties of ferroelectrics is investigated using a continuum Ginzburg-Landau model that incorporates the long-range elastic and electrostatic interactions. Microstructures with desired domain…