Tin oxide (SnO2) nanowires of different diameters can be conveniently grown by combining the chemical influence of a single‐molecular precursor [Sn(OtBu)4] with vapor–liquid–solid growth. Upon illumination with UV light at a wavelength of 370 nm, the nanowires exhibit interesting photoconductance, which can be modulated by tuning the wire diameter, as demonstrated for samples possessing radial dimensions in the range 50–1000 nm (see image).

High-yield synthesis of germanium nanowires (NWs) and core−shell structures is achieved by the chemical vapor deposition (CVD) of dicyclopentadienyl germanium ([Ge(C5H5)2]). The one-dimensional (1D) nanostructures are formed on an iron substrate following a base-growth model in which an Fe−Ge epilayer functions as a catalytic bed. The wire growth is selective and no catalyst particles are observed at the tip of the NWs, which is contrary to the characteristic feature of a 1D growth based on the vapor−liquid−solid (VLS) mechanism. The diameter and length of the NWs were in the ranges 15−20 nm and 25−40 μm, respectively, as found by high-resolution electron microscopy. Both axial and radial dimensions of the NWs can be controlled by adjusting the precursor feedstock, deposition temperature, and size of alloy nuclei in the Fe−Ge epilayer. High precursor flux produced coaxial heterostructures where single-crystalline Ge cores are covered with an overlayer of nanocrystalline Ge. Single-crystal Ge nanowires exhibit a preferred growth direction [112̄] confirmed by X-ray and electron diffraction patterns. When compared to bulk Ge, the micro-Raman spectra of Ge NWs show a low field shift, probably due to the dimensional confinement. Patterned growth of Ge NWs was achieved by shadow-masking the Fe substrate with a carbon film, which prevents the formation of Fe−Ge nuclei, thereby inhibiting the nanowire growth.

Imaging single epidermal growth factor receptors (EGFR) in intact cells is presently limited by the available microscopy methods. Environmental scanning electron microscopy (ESEM) of whole cells in hydrated state in combination with specific labeling with gold nanoparticles was used to localize activated EGFRs in the plasma membranes of COS7 and A549 cells. The use of a scanning transmission electron microscopy (STEM) detector yielded a spatial resolution of 3 nm, sufficient to identify the locations of individual EGFR dimer subunits. The sizes and distribution of dimers and higher order clusters of EGFRs were determined. The distance between labels bound to dimers amounted to 19 nm, consistent with a molecular model. A fraction of the EGFRs was found in higher order clusters with sizes ranging from 32–56 nm. ESEM can be used for quantitative whole cell screening studies of membrane receptors, and for the study of nanoparticle-cell interactions in general.

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Using the electron-beam-induced barrier currents and the Monte Carlo simulation methods it was possible to determine the depth-dose function as well as the distribution function of the generation source for electron-hole pairs perpendicular to the injection direction. The depth-dose function was compared with results obtained by Everhart and Hoff. By fitting the simulated barrier current profile to the measured one the authors could estimate the relatively small width of the space charge region of the p-n junction employed for the measurements. Furthermore, the spatial dose distribution of Si was described in an analytic approximation of the Monte Carlo simulation using two Gaussian functions concerned with the spreading of the penetrating electron beam and the diffusion of the primary electrons within the target, respectively. This approximation was based on treatments of the scattering process of the primary electrons given by Bethe and co-workers, Bothe and Archard.

Abstract.We have produced granular films based on carbon and different transition metals by means of plasma deposition processes. Some of the films possess an increased strain sensitivity compared to metallic films. They respond to strain almost linearly with gauge factors of up to 30 if strained longitudinally, while in the transverse direction about half of the effect is still measured. In addition, the film's thermal coefficient of resistance is adjustable by the metal concentration. The influence of metal concentration was investigated for the elements Ni, Pd, Fe, Pt, W, and Cr, while the elements Co, Au, Ag, Al, Ti, and Cu were studied briefly. Only Ni and Pd have a pronounced strain sensitivity at 55 ± 5 at. % (atomic percent) of metal, among which Ni-C is far more stable. Two phases are identified by transmission electron microscopy and X-ray diffraction: metal-containing nanocolumns densely packed in a surrounding carbon phase. We differentiate three groups of metals, due to their respective affinity to carbon. It turns out that only nickel has the capability to bond and form a stable and closed encapsulation of GLC around each nanoparticle. In this structure, the electron transport is in part accomplished by tunneling processes across the basal planes of the graphitic encapsulation. Hence, we hold these tunneling processes responsible for the increased gauge factors of Ni-C composites. The other elements are unable to form graphitic encapsulations and thus do not exhibit elevated gauge factors.

Core/shell nanowires of Al/Al 2 O 3 are obtained by decomposition of tert-butoxyalane on metal, silicon or glass substrates heated up to 650°C without use of a noble metal seed. These biphasic nanowires are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and high-resolution TEM. They have uniform diameters of about 20-30 nm, are composed of an inner aluminium wire, wrapped up by aluminium oxide at a constant molar ratio, and have lengths of several microAluminium metal is known to have an oxidic protection film on its surface which prevents the metal from further corrosion despite its negative potential towards hydrogen in acidic (-1.676 Volt) and basic (-2.310 Volt) media. This protection coating, so-called "passivation layer", can be further densified in the eloxal process.[1] We have been able to synthesize nanoparticles of aluminium embedded in an alumina matrix, thus protected from further reactions at ordinary conditions (water, oxygen), using a chemical gasphase reaction as shown in reaction (1). [2][3][4] The process shown in Equation (1) uses the volatile single-source precursor tert-butoxyalane [3] which, under anaerobic conditions and reduced pressure, reacts to the volatile gases hydrogen and isobutene and to the solid composite Al/Al 2 O 3 , assembling the metal and oxide phases. Contrarily to bulk aluminium (see above), the oxide layer in this nanocomposite (aluminium particle sizes ranging from 1-50 nm, depending on the synthetic conditions) [2][3][4] is stoichiometric with a molecular ratio of Al 0 /Al 3+ = 1:2. A consequence is that the aluminium oxide layer on the spherical particles is quite thick compared to the metallic core (see (1) [a] INM -Leibniz Institute for New Materials, Campus D2 2,