Related papers: Ferroelastic twin angles at the surface of CaTiO$_…
Ferroelastic twin walls in nonpolar materials can give rise to a spontaneous polarization due to symmetry breaking. Nevertheless, the bi-stable polarity of twin walls and its reversal have not yet been demonstrated. Here, we report that the…
The multiferroic properties of EuTiO3 are greatly enhanced when a sample is strained, signifying that coupling between strain and structural, magnetic or ferroelectric order parameters is extremely important. Here resonant ultrasound…
Electronic and structural phenomena at the twin domain wall-surface junctions in the ferroelastic materials are analyzed. Carriers accumulation caused by the strain-induced band structure changes originated via the deformation potential…
Based on a first-principles based multiscale approach, we study the polarity (P) of ferroelastic twin walls in SrTiO$_3$. In addition to flexoelectricity, which was pointed out before, we identify two new mechanisms that crucially…
We report on the electric field response of 180 degree nanodomain walls in BaTiO$_3$ using in situ electrical biasing in transmission electron microscopy (TEM). The sample is biased on a micro-device designed for reliable testing whose key…
Optical excitation perturbs the balance of phenomena selecting the tilt orientation of domain walls within ferroelectric thin films. The high carrier density induced in a low-strain BaTiO3 thin film by an above-bandgap ultrafast optical…
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…
In complex oxide heteroepitaxy, strain engineering is a powerful tool to obtain phases in thin films that may be otherwise unstable in bulk. A successful example of this approach is mixed phase bismuth ferrite (BiFeO3) epitaxial thin films.…
Micrometric domains of precise ferroelectric polarization have been written into a 20 nm thick epitaxial thin film of BaTiO3(001) (BTO) on a Nb doped SrTiO3 (STO) substrate using PiezoForce Microscopy (PFM). The domain dependent electronic…
We present an ab initio simulation of $90^{\circ}$ ferroelastic twins that were recently observed in methyl ammonium lead iodide. There are two inequivalent types of $90^{\circ}$ walls that we calculate to act as either electron or hole…
Recent interests towards novel functionalities arising at domain walls of ferroic materials naturally call for a microscopic understanding. To this end, first-principles calculations have been performed in order to provide solid evidence of…
The effective barrier height between an electrode and a ferroelectric (FE) depends on both macroscopic electrical properties and microscopic chemical and electronic structure. The behavior of a prototypical electrode/FE/electrode structure,…
Scanning tunneling microscopy and spectroscopy have been used to investigate the femtosecond dynamics of Dirac fermions in the topological insulator Bi$_2$Se$_3$ ultrathin films. At two-dimensional limit, bulk electrons becomes quantized…
We have constructed the surface phase diagram of the BaTiO$_{3}$(001) surface by employing an evolutionary algorithm for surface structure prediction, where the ferroelectric polarization is included as a degree of freedom. Among over 1000…
Ferroelectric domains in PbTiO$_3$/SrTiO$_3$ superlattices were studied using synchrotron X-ray diffraction. Macroscopic measurements revealed a change in the domain wall orientation from $\left\lbrace 100 \right\rbrace $ to $\left\lbrace…
Ferroic materials are well known to exhibit heterogeneity in the form of domain walls. Understanding the properties of these boundaries is crucial for controlling functionality with external stimuli and for realizing their potential for…
Epitaxial strain is a powerful means to engineer emergent phenomena in thin films and heterostructures. Here, we demonstrate that KTaO3, a cubic perovskite in bulk form, can be epitaxially strained into a highly tunable ferroelectric. KTaO3…
Recent works have shown that the domain walls of room-temperature multiferroic BiFeO3 (BFO) thin films can display distinct and promising functionalities. It is thus important to understand the mechanisms underlying domain formation in…
In purely c-axis oriented PbZr$_{0.2}$Ti$_{0.8}$O$_3$ ferroelectric thin films, a lateral piezoresponse force microscopy signal is observed at the position of 180{\deg}domain walls, where the out-of-plane oriented polarization is reversed.…
Ferroelectric domain nucleation and growth in multiferroic BiFeO3 films is observed directly by applying a local electric field with a conductive tip inside a scanning transmission electron microscope. The nucleation and growth of a…