相关论文: Electrostatic stability of insulating surfaces: Th…
Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely…
Polar crystal surfaces play an important role in the functionality of many materials, and have been studied extensively over many decades. In this article, a theoretical framework is presented that extends existing theories by placing the…
Crystal surfaces are sensitive to the surrounding environment, where atoms left with broken bonds reconstruct to minimize surface energy. In many cases, the surface can exhibit chemical properties unique from the bulk. These differences are…
With ab initio codes that employ three-dimensional periodic boundary conditions, the slab-and-vacuum model has proven invaluable for the derivation of energetic, atomistic, and electronic properties of materials. Within this approach, polar…
Ionic crystals, such as solid electrolytes and complex oxides, are central to modern technologies for energy storage, sensing, actuation, and other functional applications. An important fundamental issue in the atomic and quantum-scale…
Thermodynamic theory is developed for the ferroelectric phase transition of an ultrathin film in equilibrium with a chemical environment that supplies ionic species to compensate its surface. Equations of state and free energy expressions…
Polar crystals composed of charged ionic planes cannot exist in nature without acquiring surface changes to balance an ever-growing dipole. The necessary changes can manifest structurally or electronically. An electronic asymetry has long…
The electronic and atomic structure of several $(1\times 1)$ terminations of the (110) polar orientation of SrTiO$_3$ surface are systematically studied by first-principles calculations. The electronic structure of the two stoichiometric…
This work presents a fast and scalable approach for predicting surface stability and equilibrium crystal morphology in ionic materials using electrostatic analysis. The method constructs stoichiometric slab terminations and evaluates their…
When insulator LaAlO3 is grown by epitaxy onto a TiO2-terminated {100} surface of insulator SrTiO3, the resulting system has a metallic character. This phenomenon has been associated with an electrostatic frustration at the interface, as…
The question of stability against diffusional mixing at the prototypical LaAlO3/SrTiO3(001) interface is explored using a multi-faceted experimental and theoretical approach. We combine analytical methods with a range of sensitivities to…
We discuss the relation between bulk topological invariants and the spectrum of surface states in three dimensional non-interacting topological insulators. By studying particular models, and considering general boundary conditions for the…
Using density-functional theory in combination with a thermodynamic formalism we calculate the relative stability of various structural models of the polar O-terminated (000-1)-O surface of ZnO. Model surfaces with different concentrations…
A pronounced uniform polar distortion extending over several unit cells enables thin LaAlO3 overlayers on SrTiO3(001) to counteract the charge dipole and thereby neutralize the "polarization catastrophe" that is suggested by simple…
Three dimensional topological insulator crystals consist of an insulating bulk enclosed by metallic surfaces, and detailed theoretical predictions about the surface state band topology and spin texture are available. While several…
We discuss a non-perturbative, technically straightforward, easy-to-use, and computationally affordable method, based on polarization theory, for the calculation of the electronic dielectric constant of insulating solids at the first…
The (001) surfaces of polar perovskites BaTiO$_3$ and PbTiO$_3$ have been studied from first principles at T=0 K. For both cases of polarization, the most stable TiO-terminated interfaces show intrinsic ferroelectricity. In the topmost…
In this paper, we study electrostatic properties between two similar or oppositely charged surfaces immersed in an electrolyte solution by using mean-field approach accounting for solvent polarization and non-uniform size effect. Applying a…
We show that the growth of the heterostructure LaGaO3/SrTiO3 yields the formation of a highly conductive interface. Our samples were carefully analyzed by high resolution electron microscopy, in order to assess their crystal perfection and…
Rearrangement of atoms due to broken translational symmetries at the surface of SrTiO$_3$ is scarcely debatable in the present day scenario. Actual concern demands to unveil the true structure and precise mechanism responsible for atomic…