One of the main goals of the multidisciplinary field of nanotechnology is to scale down electronic devices to the range of nanometers (nm) from the present feature size of ∼50 nm in standard semiconductor integrated circuits. This challenge requires the use of small molecules or clusters to perform as electronic devices. Because a multitude of small organic molecules and clusters can be tailored to precise configurations emulating feature sizes equivalent to fractions of angstroms (10-10 m), they are potential electronic device candidates. Although it is not yet well established how these small systems can be addressed, they could be used as electronic devices if they present switching behavior. However, switching alone may not be enough; more complex nonlinear current−voltage (I−V) characteristics such as negative differential resistance (NDR) already reported in several experiments may be needed to compensate for the lack of direct addressing. It is demonstrated theoretically in this work that switching and NDR can be achieved because of electronic and electromechanical effects yielding cluster formation; therefore, electronic devices can be made not only from organic molecules but also from small clusters.

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Reproducible negative differential resistance (NDR)-like switching behavior is observed in NanoCells. This behavior is attributed to the formation of filaments and clusters between the discontinuous gold films. Control experiments are performed by self-assembly of insulating molecules between the gold islands and conducting molecules on these islands. Additional control experiments are performed by removing the filaments and clusters between islands using a piranha bath. The results are consistent with theoretical predictions and extend the domain of molecular electronics based in organic molecules to include nanosized clusters as active units. This facilitates a scenario where synthetically accessible organic molecules, with defined characteristics, can be adjusted by metallic nanoclusters as an in situ fine-tuning element, able to compensate for the lack of addressing in the nanosize regime.

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Epitaxial strontium titanate films grown by atomic layer deposition on SrTiO3-buffered Si(001) substrates J.Interfacial reactions in epitaxial Al/TiN(111) model diffusion barriers: Formation of an impervious self-limited wurtzite-structure AIN(0001) blocking layer Cubic HfN ͑B1-NaCl͒ thin films were grown epitaxially on Si͑001͒ substrates by using a TiN ͑B1-NaCl͒ buffer layer as thin as ϳ10 nm. The HfN / TiN stacks were deposited by pulsed laser deposition with an overall thickness below 60 nm. Detailed microstructural characterizations include x-ray diffraction, transmission electron microscopy ͑TEM͒, and high resolution TEM. The electrical resistivity measured by four-point probe is as low as 70 ⍀ cm at room temperature.Preliminary Cu diffusion tests show a good diffusion barrier property with a diffusion depth ͑2 ͱ D͒ of 2 -3 nm after annealing at 500°C for 30 min in vacuum.

Highlights Chemical removal of anodic aluminium oxide templates can damage embedded structures. Anodic aluminium oxide templates were used to grow cuprous oxide nanorod arrays. Electrochemical removal technique prevented reduction of cuprous oxide nanorods. Reported procedure is useful in production of antimicrobial surfaces.

We deposited epitaxial and highly textured cubic HfN (B1-NaCl) thin films on single-crystal MgO (001) and Si (001) substrates, respectively, using a pulsed laser deposition technique. The HfN thin films are around 100 nm thick. Detailed microstructural characterizations, including x-ray diffraction, transmission electron microscopy (TEM), and high-resolution TEM, were carried out. Resistivity as low as 40 lX cm was observed by standard fourpoint probe measurements. The low resistivity and good diffusion barrier properties demonstrated by our preliminary Cu-diffusion tests for HfN on Si suggest that HfN could be a promising candidate diffusion barrier for Cu interconnects.