Nanometer scale

Schneir J, Harary H H, Dagata J A, Hansma P Kand Sonnenfeld R 1989 Scanning tunneling microscopy and fabrication of nanometer scale structure at the liquid-gold interface Scanning Microsc. 3 719... 

Information on the morphology of the nanohybrid sorbents also was revealed with SEM analysis. Dispersed spherical polymer-silica particles with a diameter of 0.3-5 pm were observed. Every particle, in one s turn, is a porous material with size of pores to 200 nm and spherical particles from 100 nm to 500 nm. Therefore, the obtained samples were demonstrated to form a nanometer - scale porous structure. 

Carpick, R.W., Enachescu, M., Ogletree, D.F. and Salmeron, M., Making, breaking, and sliding of nanometer-scale contacts. In Beltz, G.E., Selinger, R.L.B., Kim, K.-S. and Marder, M.P., (Eds.), Fracture and Ductile vs. Brittle Behavior-Theory, Modeling and Experiment. Materials Research Society, Warrendale, PA, 1999, pp. 93-103. 

Wahl, K.J., Stepnowski, S.V. and Unertl, W.N., Viscoelastic effects in nanometer-scale contacts under shear. Tribal. Lett., 5, 103-107 (1998). 

R. Saito, G. Dresselhaus, M. Fujita, and M. S. Dresselhaus, 4th NEC Symp. Phys. Chem. Nanometer Scale Mats. (1992). 

The preparation of PCNTs from benzene has been reported by Endo et al. [17-20], The process is essentially similar to that used for VGCFs described above, but without secondary wall-thickening phase (see Fig. 2). Thus PCNTs can be regarded as the precursor for VGCFs, but having a much smaller nanometer-scale... 

The main technique employed for in situ electrochemical studies on the nanometer scale is the Scanning Tunneling Microscope (STM), invented in 1982 by Binnig and Rohrer [62] and combined a little later with a potentiostat to allow electrochemical experiments [63]. The principle of its operation is remarkably simple, a typical simplified circuit being shown in Figure 6.2-2. 

Copper electrodeposition on Au(111) Copper is an interesting metal and has been widely investigated in electrodeposition studies from aqueous solutions. There are numerous publications in the literature on this topic. Furthermore, technical processes to produce Cu interconnects on microchips have been established in aqueous solutions. In general, the quality of the deposits is strongly influenced by the bath composition. On the nanometer scale, one finds different superstmctures in the underpotential deposition regime if different counter-ions are used in the solutions. A co-adsorption between the metal atoms and the anions has been reported. In the underpotential regime, before the bulk deposition begins, one Cu mono-layer forms on Au(lll) [66]. 

Besides the classical search for linear, one-dimensional electronically active materials, synthetic approaches are now also focussed on the generation and characterization of two- and three-dimensional structures, especially shape-persistent molecules with a well-defined size and geometry on a nanometer-scale. It is therefore timely and adequate to extend concepts of materials synthesis and processing to meet the needs defined by nanochcmislry since the latter is now emerging as a subdiscipline of material sciences. 

Varesi J, Majumdar A (1998) Scanning joule expansion microscopy at nanometer scales. Appl Phys Lett 72 37-39... 

Electrochemistry is the basis of many important and modem applications and scientific developments such as nanoscale machining (fabrication of miniature devices with three dimensional control in the nanometer scale), electrochemistry at the atomic scale, scanning tunneling microscopy, transformation of energy in biological cells, selective electrodes for the determination of ions, and new kinds of electrochemical cells, batteries and fuel cells. 

Gnecco, E., Beimewitz, R., Gyalog, T., and Meyer, E., "Friction Experiments on the Nanometer Scale, /. Phys. Con-dens. Matter, Vol. 13,2001,pp.R619-R642. 

After the micro wear tests, the dependence of worn depth of PTFE and PTFE/Si3N4 film on load is shown in Fig. 13. The worn depth of both PTFE and PTFE/Si3N4 film is in the nanometer scale. It can be seen that the worn depth increases linearly with load. However, the worn depth of PTFE/Si3N4 multilayers is about one-tenth of PTFE film at the same load. All these results demonstrate that the wear resistance of PTFE/Si3N4 multilayers is greatly improved after micro-assembling of soft and hard layers. 

Though most experiments get similar results, some special results are also obtained in the measurements, e.g., the result shown in Fig. 31. The surface roughness of the point in the experiments of Fig. 31 is a little larger than for most other parts of the film. This shows that the topography of the L-B film plays an important role in the friction properties obtained by using FFM measurement. Therefore having the well-prepared and highly ordered L-B film is one important factor for friction measurements. However, results like the one shown in Fig. 31 can still be accepted. Because there are so many factors that can affect the experiment results at the nanometer scale, more experiments need to be done. 

As is known, microscale friction and wear is important in microtribology. However, it is not easy to get real friction force on micro/nano scale during the tests. The surface morphology at nanometer scale, the scanning direction of the FFM, etc., have significant effects on friction force measurement. Even nowadays for commercial SPM we are not quite sure if the friction force we get is a real one or not. 

First we analyzed the states of a tip scanning along an ascent and descent surface on nanometer scale, and then we calibrated the lateral force obtained by the FFM we modified. It may be helpful to understand how to measure the true lateral force by an FFM. 

Lieber, C.M., Morales, A.M., Sheehan, P.E., Wong, E.W., and Yang, P., Chemistry on the Nanometer Scale Proceedings of Robert A. Welch Eoundation 40th Conference on Chemical Research (Houston, TX), 1996. 

Boker A., Muller A.H.E., and Krausch G., Functional ABC triblock copolymers for controlled surface patterns of nanometer scale, Polym. Mater. Sci. Eng., 84, 312, 2001. 

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