We develop a simple model to compute the energy-dependent decay factors of metal-induced gap states in metal/insulator interfaces considering the collective behavior of all the bulk complex bands in the gap of the insulator. The agreement between the penetration length obtained from the model (considering only bulk properties) and full first-principles simulations of the interface (including explicitly the interfaces) is good. The influence of the electrodes and the polarization of the insulator are analyzed. The method simplifies the process of screening materials to be used in Schootky barriers or in the design of giant tunneling electroresistance and magnetoresistance devices.

We report a facile way to fabricate three-dimensional (3D) Ni–TiO2 core–shell nanowire arrays through anodic aluminum oxide template-assisted sol–gel TiO2 nanotube shell growth followed by Ni core using room temperature constant current electrodeposition. The 3D Ni–TiO2 nanowire-based dye-sensitized solar cell (DSSC) endows a 67% increase in conversion efficiency as compared with the TiO2 nanotube DSSC and maximum conversion efficiency of 5.07% was obtained by surface treating the photoanode with TiCl4, which provides enhanced light scattering and surface passivation. Indeed, this work paves the way to build reliable 3D Ni–TiO2 nanostructured photoanodes for highly efficient DSSCs.

Textured nickel ferrite (NFO, NiFe2O4) thin films were deposited at room temperature by chemical solution deposition onto c-plane sapphire substrates. A nanoimprint lithography technique using a polydimethylsiloxane stamp was used to transfer a pattern from a master to the thin film, which was subsequently annealed to crystallize the NFO. Atomic force microscopy scans showed good periodicity and feature profile over a large area which was confirmed with cross-sectional transmission electron microscopy. X-ray diffraction revealed textured single-phase inverse spinel NFO. Magnetic measurements of patterned thin films showed a large reduction in coercivity due to demagnetization factors.

Using an effective Hamiltonian of mutiferroic BiFeO3 (BFO) as a toy model, we explore the effect of the coefficient, C, characterizing the strength of the spin–current interaction, on physical properties. We observe that for larger C values and below a critical temperature, the magnetic moments organize themselves in a novel cycloid, which propagates along a low-symmetry direction and is associated with a structural phase transition from polar rhombohedral to a polar triclinic state. We emphasize that both of these magnetic and structural transitions are results of a remarkable self-organization of different solutions of the spin–current model.

The S-doped BiOBr composite microspheres were successfully prepared through one-pot solvothermal method. The as-prepared samples exhibit higher photocatalytic activity for the degradation of Rhodamine B and phenol under visible light irradiation, attributed to the improvement of the photo-absorption property and the narrow band gap due to the dopants of S element. The higher efficiency for photodegradation of organic pollutant endows this material with a bright perspective in purification of waste water under visible-light irradiation.

Most important advances of the last years in research and development of oxygen ion transport membrane (ITM) materials based on solid or liquid Bi2O3 are briefly given. Special attention is paid to the transport properties of novel NiO/δ-Bi2O3 and In2O3/δ-Bi2O3 ceramic and ZnO/Bi2O3 solid/liquid composites. These composites show promise for use as ITM with the oxygen permeation rate comparable with that of the state-of-the-art membrane materials. The in situ Bi2O3 melt crystallization and grain boundary wetting methods of formation of the gas-tight composites are considered.

We report here a successful fabrication of three-dimensional (3D) photoelectrodes fully coated with hydrothermally formed TiO2 nanotubes on multi-layered Ti mesh with significantly increased surface area. A near-vertical array of ~8 nm diameter nanotubes of TiO2 was also produced on the metallic surface of folded Ti mesh electrode. The multi-layered mesh was used as a 3D highly conductive electrode, as this architecture intuitively allows for light passage, reflections, and smooth water flow for possible continuous operation of water splitting reaction. By virtue of substantially increased surface area and more efficient light usage, significantly increased photocurrent densities were obtained.

There is compelling evidence for the critical role of twin boundaries (TBs) in imparting the extraordinary combination of strength and ductility to nanotwinned metals. Here, we investigate the thermal fluctuations of TBs in face-centered-cubic metals to elucidate the deformation mechanisms governing their kinetic properties using molecular dynamics simulations. Our results show that the TB motion is strongly coupled to shear deformation up to 0.95 homologous temperature. A rather unexpected observation is that coherent TBs do not exhibit any capillarity-induced fluctuations even at high temperatures, in sharp contrast to other high-angle grain boundaries.

Recently, fully reversible dislocation motion was postulated to result in hysteretic nanoindentation load–displacement loops in plastically anisotropic solids. Since microcracking can also result in hysteretic loops, here we define a new parameter, reversible displacement (RD) that can differentiate between the two. For C-plane LiTaO3 surfaces and five other plastically anisotropic solids, the RD values either increase initially or remain constant with cycling. In contradistinction, for glass and A-plane ZnO surfaces, where energy dissipation is presumably due to microcracking or irreversible dislocation pileups, respectively, the RD values decreased continually with cycling.

A Grade 4 titanium was processed by equal-channel angular pressing (ECAP)–Conform and drawing to produce an ultrafine grain (UFG) size of ~180 nm. Some samples were tested in this condition (UFG-1) and others were annealed for 1 h at 623 K (UFG-2). The grain boundaries are in a non-equilibrium condition after processing, but the annealing equilibrates the boundaries without any increase in grain size. This leads to significant differences in the mechanical behavior of UFG-1 and UFG-2 when they are tested at 293 and 623 K.

Plasma electrolysis (PE) is a combination of electrolysis and plasma discharge. Previous studies indicated that PE usually created porous surface with irregular morphology as a result of the plasma–cathode interaction that was dominated by physical reactions. This paper demonstrated that highly ordered textured silicon surfaces could be created using PE. This abnormal anisotropic etching phenomenon implied that the chemical reactions were decoupled from the physical processes and the physical reactions were suppressed. Raman spectra confirmed that the textured silicon surface created by PE conserved the crystalline structure. Therefore, PE may lead to new process regimes for surface engineering.