One mechanism of silver resistance in microorganisms is accumulation of the metal ions in the cell. Here, we report on the phenomenon of biosynthesis of silver-based single crystals with well-defined compositions and shapes, such as equilateral triangles and hexagons, in Pseudomonas stutzeri AG259. The crystals were up to 200 nm in size and were often located at the cell poles. Transmission electron microscopy, quantitative energy-dispersive x-ray analysis, and electron diffraction established that the crystals comprise at least three different types, found both in whole cells and thin sections. These Ag-containing crystals are embedded in the organic matrix of the bacteria. Their possible potential as organic-metal composites in thin film and surface coating technology is discussed.

We experimentally investigated optical, electrical, and microstructural properties of heterointerfaces between two thin-film perovskite insulating materials, ${\mathrm{SrTiO}}_3$ (STO) and ${\mathrm{LaAlO}}_3$ (LAO), deposited at different oxygen pressure conditions. Cathode and photoluminescence experiments show that oxygen vacancies are formed in the bulk STO substrate during the growth of LAO films, resulting in high electrical conductivity and mobility values. In both high and low oxygen pressure interfaces, the electrical Hall mobilities follow a similar power-law dependence as observed in oxygen reduced STO bulk samples. The results are confirmed on a microscopic level by local strain fields at the interface reaching $10\mathrm{nm}$ into the STO substrate.

Tin oxide films doped with oxygen vacancies, F, Sb, or Mo were made by reactive rf magnetron sputtering of Sn, Sn‐Sb, or Sn‐Mo in Ar+O₂(+CF₄) onto glass heated to a temperature up to 530 °C. Electrical dc resistivity, mobility, free‐electron density, spectral optical properties, and microstructure were investigated as a function of sputtering parameters. Optimized deposition parameters gave SnO_x:(Sb,F) films with high luminous transmittance, low luminous absorptance, high infrared reflectance, and dc resistivity down to 9.1×10⁻⁴ Ω cm. Refractive index n and extinction coefficient k were evaluated from spectrophotometric transmittance. In the luminous range, the films had 1.90<n<2.0 and k of the order of 10⁻². Hall‐effect measurements showed n‐type conduction with electron densities in the 10²⁰–10²¹ cm⁻³ range. Band‐gap broadening from 4.06 to 4.45 eV was observed with increasing electron density. X‐ray diffractometry and transmission electron microscopy showed that the structure factor of the films depended on the oxygen content as well as on the specific doping species. A preferred direction of film growth was probably also present. Transmission electron microscopy indicated different grain sizes, between 6 and 30 nm, depending on oxygen content, substrate temperature, and doping species. Optical and electrical properties were compared with results from a quantitative model for wide band‐gap semiconductors. The theory is based on heavy n doping by oxygen vacancies or by Sb or/and F and encompasses ionized impurity scattering of the free electrons. It was found that ionized impurity scattering, as well as an additional scattering mechanism tentatively ascribed to grain boundaries, prevailed in the films.

Here we demonstrate, for the first time experimentally, a nanopipette action for metals using multiwalled carbon nanotubes. The process relies on electromigration forces, created at high electron current densities, enabling the transport of material inside the hollow core of carbon nanotubes. In this way nanoparticles of iron were transported to and from electrically conducting substrates.