Rational Assembly of Two-Dimensional Perovskite Nanosheets as Building Blocks for New Ferroelectrics.

Artificial materials in the form of superlattices have been studied actively in quest of new engineering methods or design rules for the development of desired functionalities, in particular high- ferroelectricity, ferromagnetism, and high mobility electron gas. This work presents a controlled assembly strategy for fabricating atomically precise interfaces of two-dimensional (2D) homologous perovskite nanosheets (CaNaNbO; = 3-6) to construct artificial superlattices. The distinctive thickness of each 2D homologous perovskite nanosheets attributed to the presence of different number of NbO octahedra provides an exquisite control to engineer interfacial properties for tailored design of superior high- properties and emergence of ferroelectricity.

Scalable Design of Two-Dimensional Oxide Nanosheets for Construction of Ultrathin Multilayer Nanocapacitor.

Large size of capacitors is the main hurdle in miniaturization of current electronic devices. Herein, a scalable solution-based layer-by-layer engineering of metallic and high-κ dielectric nanosheets into multilayer nanosheet capacitors (MNCs) with overall thickness of ≈20 nm is presented. The MNCs are built through neat tiling of 2D metallic Ru O and high-κ dielectric Ca NaNb O nanosheets via the Langmuir-Blodgett (LB) approach at room temperature which is verified by cross-sectional high-resolution transmission electron microscopy (HRTEM).

Atomic Layer Engineering of High-κ Ferroelectricity in 2D Perovskites.

Complex perovskite oxides offer tremendous potential for controlling their rich variety of electronic properties, including high-T superconductivity, high-κ ferroelectricity, and quantum magnetism. Atomic-scale control of these intriguing properties in ultrathin perovskites is an important challenge for exploring new physics and device functionality at atomic dimensions. Here, we demonstrate atomic-scale engineering of dielectric responses using two-dimensional (2D) homologous perovskite nanosheets (CaNaNbO; m = 3-6).

Biomass-Derived Thermally Annealed Interconnected Sulfur-Doped Graphene as a Shield against Electromagnetic Interference.

Electrically conductive thin carbon materials have attracted remarkable interest as a shielding material to mitigate the electromagnetic interference (EMI) produced by many telecommunication devices. Herein, we developed a sulfur-doped reduced graphene oxide (SrGO) with high electrical conductivity through using a novel biomass, mushroom-based sulfur compound (lenthionine) via a two-step thermal treatment. The resultant SrGO product exhibited excellent electrical conductivity of 311 S cm(-1), which is 52% larger than 205 S cm(-1) for undoped rGO.

Artificial design for new ferroelectrics using nanosheet-architectonics concept.

Control over the emergence of ferroelectric order remains a fundamental challenge for the rational design of artificial materials with novel properties. Here we report a new strategy for artificial design of layered perovskite ferroelectrics by using oxide nanosheets (high-k dielectric Ca2Nb3O10 and insulating Ti0.87O2) as a building block.

2D perovskite nanosheets with thermally-stable high-κ response: a new platform for high-temperature capacitors.

We investigated high-temperature dielectric responses of high-κ perovskite nanosheet (Ca2Nb3O10), an important material platform for postgraphene technology and ultrascale electronic devices. Through in situ characterizations using conducting atomic force microscopy, we found a robust high-temperature property of Ca2Nb3O10 nanosheet even in a monolayer form (∼2 nm). Furthermore, layer-by-layer assembled nanocapacitors retained both size-free high-εr characteristic (∼200) and high insulation resistance (∼1×10(-7) A/cm2) at high temperatures up to 250 °C.

Endovascular stenting as a first choice for the palliation of superior vena cava syndrome.

To assess the effectiveness of endovascular stenting for the palliation of superior vena cava (SVC) syndrome, endovascular stent insertion was attempted in 10 patients with symptomatic occlusion of the SVC. All the patients had known malignant disease of the thorax. Eight patients had been treated previously with chemotherapy and radiotherapy (n=5), chemotherapy alone (n=2), or pneumonectomy and radiotherapy (n=1).

K(VO)(SeO(3))(2)H: A New One-Dimensional Compound with Strong Hydrogen Bonding.

The hydrothermal synthesis, X-ray single crystal structure, magnetic properties, and solid state NMR and infrared spectroscopic data of a new compound, K(VO)(SeO(3))(2)H, are described. K(VO)(SeO(3))(2)H crystallizes in the monoclinic space group P2(1)/m (No. 11), with a = 7.

AVSeO(5) (A = Rb, Cs) and AV(3)Se(2)O(12) (A = K, Rb, Cs, NH(4)): Hydrothermal Synthesis in the V(2)O(5)-SeO(2)-AOH System and Crystal Structure of CsVSeO(5).

Hydrothermal reactions in the V(2)O(5)-SeO(2)-AOH systems (A = Na, K, Rb, Cs, NH(4)) were studied with various reagent mole ratios. Typical millimole ratios were V(2)O(5)/SeO(2)/AOH = 5 or 3/15/x in 10-mL aqueous solutions, where x was 5, 10, 15, and 20. The reactions with x = 5 for A = K, Rb, Cs, and NH(4) at 230 degrees C produced single-phase products of the general formula AV(3)Se(2)O(12) with the (NH(4))(VO)(3)(SeO(3))(2) structure type.