Search

X-ray studies performed during the growth of CdCO3 and MnCO3 crystals from supersaturated aqueous solutions, at fatty acid monolayer templates, reveal that the nucleates are nearly three-dimensional powders below a threshold supersaturation. However, at higher supersaturations, the crystals are preferentially oriented with the {0 1 2} direction vertical. Scanning electron microscope images of samples transferred to substrates show discrete crystals at low concentrations, while at higher concentrations the crystals self-aggregate to form linear chains and sheets. The authors speculate that preferential alignment at the organic-inorganic interface is enhanced as a consequence of oriented aggregation of crystals. The role of monolayer-ion interactions in governing the morphologies and the resulting orientation of the inorganic nucleate is discussed. [ABSTRACT FROM AUTHOR]

A multiple-tip ultrahigh vacuum (UHV) scanning tunneling microscope (MTSTM) with a scanning electron microscope (SEM) for imaging and molecular-beam epitaxy growth capabilities has been developed. This instrument (nanoworkbench) is used to perform four-point probe conductivity measurements at μm spatial dimension. The system is composed of four chambers, the multiple-tip STM/SEM chamber, a surface analysis and preparation chamber, a molecular-beam epitaxy chamber, and a load–lock chamber for fast transfer of samples and probes. The four chambers are interconnected by a unique transfer system based on a sample box with integrated heating and temperature-measuring capabilities. We demonstrate the operation and the performance of the nanoworkbench with STM imaging on graphite and with four-point-probe conductivity measurements on a silicon-on-insulator (SOI) crystal. The creation of a local FET, whose dimension and localization are, respectively, determined by the spacing between the probes and their position on the SOI surface, is demonstrated. [ABSTRACT FROM AUTHOR]

In order to manufacture a carbon nanotube (CNT) tip in which the attachment angle and position of CNT were precisely adjusted, a nanomanipulator was installed inside a scanning electron microscope (SEM). A CNT tip, atomic force microscopy (AFM) probe to which a nanotube is attached, is known to be the most appropriate probe for measuring the shape of high aspect ratio. The developed nanomanipulator has two sets of modules with the degree of freedom of three-directional rectilinear motion and one-directional rotational motion at an accuracy of tens of nanometers, so it enables the manufacturing of more accurate CNT tips. The present study developed a CNT tip with the error of attachment angle less then 10° through three-dimensional operation of a multiwalled carbon nanotube and an AFM probe inside a SEM. [ABSTRACT FROM AUTHOR]