Related papers: Room temperature surface piezoelectricity in SrTiO…
Piezoelectricity is inherent only in noncentrosymmetric materials, but a piezoelectric response can also be obtained in centrosymmetric crystals if subjected to inhomogeneous deformation. This phenomenon, known as flexoelectricity, affects…
The temperature-dependent polarization of SrTiO_3 thin films is investigated using confocal scanning optical microscopy. A homogeneous out-of-plane and inhomogeneous in-plane ferroelectric phase are identified from images of the linear…
The polarization response of a material to a strain gradient, known as flexoelectricity, holds great promise for novel electromechanical applications. Despite considerable recent progress, however, the effect remains poorly understood. From…
SrTiO$_{3}$ is known to be an incipient ferroelectric. It is thought that ferroelectric stability in SrTiO$_{3}$ is suppressed by a delicate competition with quantum fluctuation and antiferrodistortion. The ferroelectric phase can, however,…
The origin of the functional properties of complex oxide superlattices can be resolved using time-resolved synchrotron x-ray diffraction into contributions from the component layers making up the repeating unit. The CaTiO3 layers of a…
The piezoelectric response is a measure of the sensitivity of a material's polarization to stress or its strain to an applied field. Using in-operando x-ray Bragg coherent diffraction imaging, we observe that topological vortices are the…
From an experimental point of view, room temperature ferroelectricity in BiFeO3 is raising many questions. Electric measurements made a long time ago on solid-solutions of BiFeO3 with Pb(Ti,Zr)O3 indicate that a spontaneous electric…
Flexoelectricity (coupling between polarization and strain gradients) is a property of all dielectric materials that has been theoretically known for decades, but it is only relatively recently that it has begun to attract experimental…
A method for evaluating the piezoelectric response of unpoled ferroelectric ceramics from elastic and dielectric measurements is proposed and tested on BaTiO$_3$. The method is based on the observation that the softening in a ferroelectric…
Since its original prediction 25 years ago, room-temperature out-of-plane ferroelectricity in compressively strained SrTiO3 remains an ongoing pursuit. In this work, we investigate the structural, electrical and electromechanical properties…
We report far-infrared dielectric properties of powder form ferroelectric SrTiO3. Terahertz time-domain spectroscopy (THz-TDS) measurement reveals that the low-frequency dielectric response of SrTiO3 is a consequence of the lowest…
SrTiO3 is an incipient ferroelectric that is believed to exhibit a prototype displacive, soft mode ferroelectric transition when subjected to mechanical stress or alloying. We use high-angle annular dark-field imaging in scanning…
The pyroelectric effect in ferroelectric thin films is typically composed of different contributions, which are difficult to disentangle. In addition, clamping to the substrate interface plays an important role. We studied epitaxial…
We revealed the anomalous temperature behavior of the giant dielectric permittivity and unusual frequency dependences of the pyroelectric response of the fine-grained ceramics prepared by the spark plasma sintering of the ferroelectric…
Theoretical analysis based on the Landau-Ginzburg-Devonshire (LGD) theory is used to show that the product effect of flexoelectricity and rotostriction can lead to a spontaneous polarization in the vicinity of antiphase boundaries,…
Room temperature ferromagnetic hysteresis is observed in commercial SrTiO$_3$ substrates purchased from a variety of suppliers. It is shown that the ferromagnetic signal comes from the unpolished surfaces. Surface impurity phases cannot be…
Ferroelectric soft mode properties in ceramics and thin films are reviewed and compared with single crystals. In general, the permittivity in ceramics and thin films is markedly reduced compared to the single crystals mainly because of…
Based on a first-principles based multiscale approach, we study the polarity (P) of ferroelastic twin walls in SrTiO$_3$. In addition to flexoelectricity, which was pointed out before, we identify two new mechanisms that crucially…
Complex electrical permittivity measurements in (1-x)[Pb(Mg1/3 Nb2/3)O3]-xPbTiO3 ceramics for 0.10 x 0.40 were performed in the frequency and temperature range from 1 kHz to 100 kHz and from 15 to 600 K, respectively. Unexpected dielectric…
Ferroelectric BiFeO3 thin films and artificial superlattices of (BiFeO3)m(SrTiO3)m (m~ 1 to 10 unit cells) were fabricated on (001)-oriented SrTiO3 substrates by pulsed laser ablation. The variation of leakage current and macroscopic…