Related papers: Ferroelectric ZrO$_{2}$ monolayers as buffer layer…
Despite being successfully synthesized [Zhang $et$ $al.$, Nat. Mater. \textbf{20}, 1073 (2021)], the monolayer structure of stable hexagonal TiO$_2$ is unknown, and it is not even clear whether it can exist in a freestanding form. Through…
Although most two-dimensional (2D) materials are non-ferroelectric with highly symmetric lattices, symmetry breaking may take place in their bilayers upon certain stacking order, giving rise to so-called sliding ferroelectricity where the…
Ferroelectric domains were investigated using piezoresponse force microscopy in superlattices composed of multiferroic BiFeO3 and SrTiO3 layers. Compared to single BiFeO3 thin films, a reduction in the domains size and a suppression of the…
The strong metal-support interaction (SMSI) leads to substantial changes of the properties of an oxide-supported catalyst after annealing under reducing conditions. The common explanation is the formation of heavily reduced, ultrathin oxide…
Contribution of d-electron to ferroelectricity of type-II multiferroics causes strong magneto-electric coupling and distinguishes them from the conventional type-I multiferroics. However, their therein polarization is too small because the…
The discovery of ferroelectricity in both pure and doped HfO$_2$-based thin films have revitalized the interest in using ferroelectrics for nanoscale device applications. To take advantage of this silicon-compatible ferroelectric,…
Using first-principles calculations, we predict that tunable ferroelectricity can be realized in oxide perovskites with the Grenier structure and ordered oxygen vacancies. Specifically, we show that $R_{1/3}A_{2/3}\mathrm{FeO}_{2.67}$…
We report on the structural and magnetic properties of a cobalt-implanted ZnO film grown on a sapphire substrate. X-ray diffraction and transmission electron microscopy reveal the presence of a (10-10)-oriented hexagonal Co phase in the…
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…
Two-dimensional materials with ferroelectric properties break the size effect of conventional ferroelectric materials and unlock unprecedented potentials of ferroelectric-related application at small length scales. In this work, using…
The formation of a two-dimensional electron gas at oxide interfaces as a consequence of polar discontinuities has generated an enormous amount of activity due to the variety of interesting effects it gives rise to. Here we study under what…
The conductance confined at the interface of complex oxide heterostructures provides new opportunities to explore nanoelectronic as well as nanoionic devices. Herein we show that metallic interfaces can be realized in SrTiO3-based…
Interfaces can differ from their parent compounds in terms of charge, spin, and orbital orders and are fertile ground for emergent phenomena, strongly correlated physics, and device applications. Here, we discover that ferroelectric order…
The bistability of charge polarization in ferroelectric materials has long been the basis of ferroelectric devices. However, the ferroelectricity tends to be vanishing as the thickness of materials is reduced to a few nanometers or thinner…
First-principles calculations based on density-functional theory in the pseudo-potential approach have been performed for the total energy, crystal structure and cell polarization for SrTaO$_2$N/SrTiO$_3$ heterostructures. Different…
SrTiO$_3$ is an incipient ferroelectric on the verge of a polar instability, which is avoided at low temperatures by quantum fluctuations. Within this unusual quantum paraelectric phase, superconductivity persists despite extremely dilute…
Ferroelectricity observed in thin film $\mathrm{HfO_2}$, either doped with Si, Al, etc. or in the $\mathrm{Hf_{0.5}Zr_{0.5}O_2}$ form, has gained great technical significance. However, the soft mode theory faces a difficulty in explaining…
Atomically sharp oxide heterostructures often exhibit unusual physical properties that are absent in the constituent bulk materials. The interplay between electrostatic boundary conditions, strain and dimensionality in ultrathin epitaxial…
PbTiO$_3$ is a simple but very important ferroelectric oxide that has been extensively studied and widely used in various technological applications. However, most previous studies and applications were based on the bulk material or the…
We report a systematic first-principles study based on density functional theory (DFT) of the structural and ferroelectric properties of the $R_2$Ti$_2$O$_{7}$ perovskite-related oxides with $R=$ La, Ce, Pr, and Nd. We show that, in all…