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Long-range (>10 μm) transport of electrons along networks of Geobacter sulfurreducens protein filaments, known as microbial nanowires, has been invoked to explain a wide range of globally important redox phenomena. These nanowires were previously thought to be type IV pili composed of PilA protein. Here, we report a 3.7 Å resolution cryoelectron microscopy structure, which surprisingly reveals that, rather than PilA, G. sulfurreducens nanowires are assembled by micrometer-long polymerization of the hexaheme cytochrome OmcS, with hemes packed within ∼3.5-6 Å of each other. The inter-subunit interfaces show unique structural elements such as inter-subunit parallel-stacked hemes and axial coordination of heme by histidines from neighboring subunits. Wild-type OmcS filaments show 100-fold greater conductivity than other filaments from a ΔomcS strain, highlighting the importance of OmcS to conductivity in these nanowires. This structure explains the remarkable capacity of soil bacteria to transport electrons to remote electron acceptors for respiration and energy sharing.

The structure, stability and electron conductivity of LiVPO 4 F covered by MoS 2 were investigated by a first-principles method based on density functional theory. Calculations show that the low-index LiVPO 4 F (010) surface exposing Li and O atoms is the lowest energy surface. The formation of a new surface-state near the Fermi level reduces the band gap of the LiVPO 4 F surface compared to that of the bulk. For clean LiVPO 4 F surfaces, the quantum state near the Fermi level is dominated by the V-3 d orbital. In addition, PDOS of V atoms shows significant differences in different atomic layers. MoS 2 coating dramatically increases the stability of the LiVPO 4 F surface by forming strong covalent bonds with this surface. Additionally, it also enhances the electronic conductivity by reducing the band gap and generating new electronic states at the Fermi level. These theoretical results are consistent with experimental data. [ABSTRACT FROM AUTHOR]

In this paper, the anisotropic magnetoresistance (AMR) and electron conductivity of electron gas in presence of the Rashba and Dresselhaus spin-orbit coupling are investigated. Boltzmann equation is solved exactly for low temperature, including electron scattering. Calculations have been performed within the coherent potential approximation. Results of the transport study demonstrate that the AMR enhances as the Rashba strength increases. It is also observed that the AMR depends critically on spin-orbit coupling strength, wave vector and Dresselhaus strength. [ABSTRACT FROM AUTHOR]

Abstract: The sensing properties of direct-patternable TiO2 thin films prepared by photochemical solution deposition were improved by the incorporation of multi-wall carbon nanotubes (MWCNTs). Upon incorporation of the MWCNTs, the crystallinity of the TiO2 thin films containing MWCNTs did not change. However, the electron conductivity was improved due to the π-bond nature of the MWCNT surface. In addition, an increase in the oxidation ratio on the surface of the TiO2 thin films upon MWCNT incorporation caused an increase in surface area. Because of the high electron conductivity and surface area of the MWCNT-incorporated TiO2 sensor, the sensitivity of the sensor was enhanced from 2.19 to 89.2. Direct-patterning of MWCNT-incorporated TiO2 thin films can be performed without a photoresist or etching process. These results suggest that a micro-patterned sensor can be simply fabricated at a low cost and the sensitivity of TiO2 thin films can be improved by incorporating MWCNTs. [Copyright &y& Elsevier]

• Ultrathin Zn-defect ZnNi LDH nanosheets were uniformly anchored on CuO nanowires via a ZIF-8 derived route. • Zn vacancies in the nanosheets regulates the electronic structures, and offers sufficient unsaturated metal active sites. • Ultrathin nanosheets coated on nanowire skeletons avoid the aggregation and additional conductive additives. • Hierarchical Zn vacancies sample displays high area capacity of 3967 mF cm−2 at a current density of 2.0 mA cm−2. Designing metal-cation defects with desired architectures is a big challenge for boosting electrochemical performances. Herein, we report ultrathin ZnNi layered double hydroxide (LDH) nanosheets with rich Zn vacancies (V Zn) uniformly anchored on CuO nanowire skeletons for high performance capacitive electrode via a zeolitic imidazolate frameworks-8 derived approach. The optimized V Zn -defect electrode displays high area capacity of 3967 mF cm−2 at a current density of 2.0 mA cm−2. Moreover, an all solid-state hybrid supercapacitor constructed with the V Zn -defect sample and activated carbon delivers a maximum energy density of 1.03 mWh cm−3 at a power density of 9.3 mW cm−3. Mechanism studies indicate that V Zn regulates the electronic structure of ZnNi LDH nanosheets for electron conductivity and surface Faradaic reactions. The work may disclose the role of metal-cation defects in affecting the electrochemical activity at atomic level for developing high performance supercapacitors. Zn vacancies in ZnNi LDH nanosheets regulates the electronic structures, offers sufficient unsaturated metal active sites, and increase the electrical conductivity for SCs. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Electrical conductivity and dielectric constant have been researched in a series of crystals LiNbO 3 :Zn(~4.0–9.0 mol% ZnО in a melt) by application of constant voltage with a couple of electrodes (~<500 K) and impedance spectroscopy (~>500 К). In order to compare results we have also researched electrical conductivity σ dc of congruent LiNbO 3congr and magnesium doped LiNbO 3 :Mg crystals. We have established that electron contribution to electrical conductivity of doped crystals LiNbO 3 :Zn and LiNbO 3 :Mg is greatly smaller than that of a congruent crystal LiNbO 3congr. A decrease in conductivity is apparently connected with a restructure of LiNbO 3 crystals at high concentrations of magnesium and zinc. Doping of crystals with Zn leads to drastic changes not only in the electron conductivity area (T < 500 K), but also in a lithium ion conductivity area (Т > 500 K). At this, parameters of temperature dependence of lithium ion conductivity depend on both zinc concentration and crystallographic orientation of samples. • Electron contribution to conductivity is lower in LN doped by Zn, Mg than in pure LN. • Strong restructure occurs in LN crystals lattice at high concentration of Zn, Mg. • Electrical properties of LiNbO 3 :Zn change in the Li ion conductivity area (Т > 500 K). • Conductivity jumps at 800 K in LN crystals with a certain concentration of Zn. • It is connected with a jump-like injection of charge carriers. [ABSTRACT FROM AUTHOR]

Ce 0.1 Sr 0.9 FeO 3− δ was synthesized via a solid-state reaction in air and confirmed to be single-phase with the cubic perovskite structure (SG Pm 3 ¯ m). The oxygen content variation in the oxide was measured by a thermogravimetric technique in air from room temperature to 950 °С, and by a coulometric titration at 950 °С in the range of oxygen partial pressure (p O 2) from 10−15 atm to 0.5 atm. Electrical conductivity (σ) was measured by a four-probe dc technique in the p O 2 interval of 10−18–0.5 atm at 750–950 °С. Partial contributions to total conductivity from oxygen ions, electrons, and holes were separated, based on their different dependence on oxygen partial pressure. The obtained data were used to estimate oxygen flux density (j O 2) through the oxide membrane. The obtained characteristics were compared with those of La 0.5 Sr 0.5 FeO 3− δ as the most promising ferrite for an oxygen membrane material. While oxygen-ion and hole conductivity were higher in La 0.5 Sr 0.5 FeO 3− δ , Ce 0.1 Sr 0.9 FeO 3− δ had higher electron conductivity. Though oxygen flux density 8 ml·cm−2 min−1, calculated for a membrane of Ce 0.1 Sr 0.9 FeO 3− δ under partial methane oxidation conditions was ~25% lower than that for La 0.5 Sr 0.5 FeO 3− δ it characterized this oxide as a promising membrane material. • Oxygen non-stoichiometry and transport properties of Ce 0.1 Sr 0.9 FeO 3− δ are studied. • Cerium introduction increases oxygen deficiency in SrFeO 3−δ under ambient conditions. • The n-type conductivity in Ce 0.1 Sr 0.9 FeO 3− δ is 50% higher than that in SFeO 3−δ. • The Ce 0.1 Sr 0.9 FeO 3− δ membrane should give an oxygen flux density of 8 ml·min−1 cm−2. [ABSTRACT FROM AUTHOR]