相关论文: Electrically driven octahedral rotations in SrTiO3…
Antiferroelectrics, which host both polar and antipolar order parameters, are characterized by the double hysteresis loops which are advantageous for various applications such as high-density energy storage. In this study, we investigate…
Rotations and distortions of oxygen octahedra in perovskites play a key role in determining their functional properties. Here we investigate how octahedral rotations can couple from one material to another in…
Engineering oxygen octahedra rotation patterns in $ABO_3$ perovskites is a powerful route to design functional materials. Here we propose a strategy that exploits point defects that create local electric dipoles and couple to the oxygen…
In recent years, methods have been developed that allow first-principles electronic-structure calculations to be carried out under conditions of fixed electric field. For some purposes, however, it is more convenient to work at fixed…
Perovskite ABO$_3$ oxides display an amazing variety of phenomena that can be altered by subtle changes in the chemistry and internal structure, making them a favorite class of materials to explore the rational design of novel properties.…
Rotation of MO6 (M = transition metal) octahedra is a key determinant of the physical properties of perovskite materials. Therefore, tuning physical properties, one of the most important goals in condensed matter research, may be…
PbTiO$_3$/SrTiO$_3$ artificial superlattices recently emerged as a prototypical platform for the emergence and study of polar topologies. While previous studies mainly focused on the polar textures inherent to the ferroelectric PbTiO$_3$…
We use molecular dynamics simulations to understand the mechanisms of polarization switching in ferroelectric BaTiO$_3$ achieved with external electric field. For tetragonal and orthorhombic ferroelectric phases, we determine the switching…
We investigate the structure--property relationships in $AB$O$_3$ perovskites exhibiting octahedral rotations and cooperative octahedral breathing distortions (CBD) using group theoretical methods. Rotations of octahedra are ubiquitous in…
Distortions of the oxygen octahedra influence the fundamental electronic structure of perovskite oxides, such as their bandwidth and exchange interactions. Utilizing a fully ab-initio methodology based on density functional theory plus…
We present a systematic first-principles study of the structural and vibrational properties of perovskite-structure EuTiO3. Our calculated phonon spectrum of the high-symmetry cubic structural prototype shows strong M- and R-point…
We report the existence of a two-dimensional electron system (2DES) at the (001) surface of CaTiO3. Using angle-resolved photoemission spectroscopy, we find a hybridization between the d_xz and d_yz orbitals, not observed in the 2DESs at…
We use first-principles methods to study oxygen-octahedra rotations in ABO3 perovskite oxides. We focus on the short-period, perfectly antiphase or in-phase, tilt patterns that characterize most compounds and control their physical (e.g.,…
The rotational instability of the electric polarization P during phase transformations between ferroelectric phases is of great practical interest, since it may be accompanied by extremely large values of the piezoelectric coefficient, and…
Layers of perovskites, found in 3D materials, 2D heterostructures, and nanotubes, often distort from high symmetry to facilitate dipole polarisation that is exploitable in many applications. Using density-functional theory calculations,…
Lead-free antiferroelectric perovskite $\rm AgNbO_3$ is nowadays attracting extensive research interests due to its promising applications in energy storage. Although great progress has been made in optimizing the material performance,…
Interface engineering in perovskite oxide superlattices has developed into a flourishing field, enabling not only further tuning of the exceptional properties, but also giving access to emergent physical phenomena. Here, we reveal a new…
We use density functional theory to explore the interplay between octahedral rotations and ferroelectricity in the model compound SrTiO$_3$. We find that over the experimentally relevant range octahedral rotations suppress ferroelectricity…
Combining effective Hamiltonian and direct $ab$ $initio$ computation, we obtain the phase diagram of SnTiO$_{3}$ with respect to epitaxial strain and temperature, demonstrating the complex features of the phase diagram and providing insight…
We analyze recent measurements [R. Blinc, V. V. Laguta, B. Zalar, M. Itoh and H. Krakauer, J. Phys. : Cond. Mat., v.20, 085204 (2008)] of the electric field gradient on the oxygen site in the perovskites SrTiO3 and BaTiO3, which revealed,…