A transparent stretchable conductor, in which well‐aligned CNT ribbons are embedded in poly(dimethylsiloxane) (PDMS) (CNT/PDMS film), is presented. Due to the good inter‐tube contact and stable CNT arrangement in the CNT ribbons, the CNT/PDMS film can maintain stable conductivity under repetitive stretching to strains up to 100%.

Self-organization of colloidal Pt nanocubes into two types of distinct ordered superlattices, simple-cubic and body-centered-tetragonal structures, has been achieved using a home-built setup. Detailed translational and orientational characteristics of these superstructures were determined using a transmission electron microscopy tomographic technique with 3D reconstruction analysis. The formation of these distinct superlattices is the result of a delicate choice of solvent (i.e., aliphatic hexane or aromatic toluene hydrocarbons), which serves as a dispersion medium to fine-tune the relative strengths of ligand-ligand and ligand-solvent interactions during the self-assembly process. This work provides important insights into the effects of ligand-solvent interactions on superlattice formation from nonspherical nanoparticles.

High critical current densities (J c ) > 1 MA/cm 2 were realized in cobalt-doped BaFe 2 As 2 (BaFe 2 As 2 :Co) films on flexible metal substrates with biaxially-textured MgO base-layers fabricated by an ion-beam assisted deposition technique. The BaFe 2 As 2 :Co films showed small in-plane crystalline misorientations ( BaFe2As2:Co ) of ~3 o regardless of twice larger misorientaions of the MgO base-layers ( MgO = 7.3 o ), and exhibited high self-field J c up to 3.5 MA/cm 2 at 2 K. These values are comparable to that on MgO single crystals and the highest J c among iron pnictide superconducting tapes and wires ever reported. High in-field J c suggests the existence of c-axis correlated vortex pinning centers. --------------------------------------------------------Footnotes:(*) Electronic mail: hosono@msl.titech.ac.jp J c (H//c) curves monotonically decrease with increasing H, but the slopes (dJ c /dH) for Film/IBAD are smaller than those for Film/sc-MgO, which would originate from a stronger vortex pinning effect along the c-axis and also from the higher T c with high irreversibility field of the Film/IBAD. Figure 3 (b) shows the J c (H//ab) and J c (H//c) dependences at 4-18 K for Film/IBAD with  MgO = 6.1 o . J c (H//ab) is larger than J c (H//c) in almost the whole H range at 4 K, while crossovers are observed at 5.0 T at 12 K and 2.9 T at 16 K, respectively. At a higher T of 18 K, J c (H//c) is greater than J c (H//ab) in the whole H region. These results are different from the J c (H) curves for T. Katase et al. 8 BaFe 2 As 2 :Co single crystals, which show the relation of J c (H//ab) > J c (H//c) in the whole H and T region 29 that is reasonable based on the intrinsic anisotropy of H c2 (i.e.;H c2 //ab > H c2 //c) 6 . These results suggest the existence of strong vortex pinning centers along the c-axis in Film/IBAD, which is effective at high T ≥ 12 K in the low H region less than several T. The inset figure plots the pinning force density F p = J c × 0 H as a function of H measured in H//c at T = 4-18 K. Each F p curve takes a peak (F pmax ) as indicated by arrows in the inset at T ≥ 12 K. The largest F pmax is ~8 GN/m 3 at 4 K but is three times smaller than those of BaFe 2 As 2 :Co epitaxial films on LSAT single crystals (30 GN/m 3 at ~12 T) 30 . It suggests that much higher in-field J c would be realized on IBAD substrates by further optimizing the c-axis correlated pinning centers.In conclusion, we demonstrated high self-field J c = 1.2-3.6 MA/cm 2 at 2 K for BaFe 2 As 2 :Co films directly grown on IBAD-MgO buffered flexible metal substrates.The biaxially-textured BaFe 2 As 2 :Co films exhibited excellent in-plane alignment with  BaFe2As2:Co ~3 o regardless of the larger  MgO = 5.5-7.3 o of the MgO base-layers. The in-field J c of the BaFe 2 As 2 :Co films on the IBAD substrates is substantially higher than that for BaFe 2 As 2 :Co films on MgO single crystals, probably due to c-axis vortex pinning effects. These results imply that high J c coated conductors can be fabricated with BaFe 2 As 2...

The high upper critical field characteristic of the recently discovered iron-based superconducting chalcogenides opens the possibility of developing a new type of non-oxide high-field superconducting wires. In this work, we utilize a buffered metal template on which we grow a textured FeSe 0.5 Te 0.5 layer, an approach developed originally for high temperature superconducting coated conductors. These tapes carry high critical current densities (>1×10 4 A/cm 2 ) at about 4.2 K under magnetic field as high as 25 T, which are nearly isotropic to the field direction. This demonstrates a very promising future for iron chalcogenides for high field applications at liquid helium temperatures. Flux pinning force analysis indicates a point defect pinning mechanism, creating prospects for a straightforward approach to conductor optimization.

Solutions in which one of the components is a high polymer and the other component is a small-molecule solvent behave in a markedly different manner than do solutions of low molecular weight components. For example, the latter obey Raoult's law if the heat of mixing is negligible; however, many polymer solutions show pronounced deviation from ideality even at concentrations of one percent or less (Figures 1–7). These deviations are due to enthalpy and entropy effects which arise from large differences in size between solvent and solute molecules. Ability to predict the solubility characteristics of polymer/solvent systems, and to calculate values of the colligative properties of such systems, is important in engineering studies of polymer processes. This paper presents a compilation of data which can be used in conjunction with the Flory-Huggins theory of polymer solutions to predict properties of polymer solutions. A method is given for predicting polymer/solvent interaction parameters (μ) for systems for which experimental data are not available. Also included is a comparison between the proposed method and two other semiempirical methods for predicting μ.