Tilted illumination exit-wave restoration is compared for two aberration-corrected instruments at different accelerating voltages. The experimental progress of this technique is also reviewed and the significance of off-axial aberrations examined. Finally, the importance of higher order aberration compensation combined with careful correction of the lower order aberrations is highlighted.

Nanosized semiconductors have been highly desirable as optoelectronic materials since the discovery of photoluminescence from porous nanostructured silicon. There are many investigations about visible light emission from nanostructured semiconductors, and several studies showed the size dependence of the photoluminescent and electronic property [1], [2]. In order to investigate the size effect of those optical properties of nanoparticles, the size-selection technique is important.

Size-selection of silicon nanoclusters has been carried out by crossing, an Ar molecular beam perpendicularly to the silicon cluster beam. The laser ablation in inert gas method was used for fabricating nanometer-sized silicon. Large size silicon clusters are produced by Nd:YAG laser irradiation of a silicon wafer which was rotating in ablation chamber under He-gas flow. Produced nanoparticles were extracted through a nozzle ( ϕ = 0.6 mm) to a differentially pumped chamber and then skimmed into a high vacuum chamber for size selection and deposition.

The nano-structure science have become popular as the nano-fabrication technology has progress recently. Among the nano-structures, the nano-wires have been attracted attention because they show quantized conductance which would be used in quantum devices[l]. The quantized conductance has been observed even at room temperature with the nano-wires prepared by tip-indentation in scanning tunneling microscope [2-4]. However, the direct observation of the nano-wires has not been examined because of lack of their stability and difficulty of specimen preparation.

We have generated a gold thin wire with the thickness ranged 0.8-2 nm, referred to as a nano bridge (NB)[5], in an ultrahigh vacuum transmission electron microscope (UHVTEM) [6]. The NB is stable at room temperature and shows good reproducibility. The shape of NB is surprisingly uniform (see Fig. 2). The structure is stabilized by stable hexagonally-closed-pack (hcp) planes for the NB of 2 nm in thickness [5]. The well-defined structure provide a good opportunities for applied and theoretical studies.

Fullerenes have many families such as simple ball-shaped fullerenes, nanotubes, and onions. Additionally torus, Y-shaped particle, and graphitic network with periodic holes or dimples have been theoretically anticipated. The presence of various shapes in fullerenes is mainly attributed to the combination of five-membered and seven-membered rings in addition to six-membered rings composing ordinary graphite crystal. The five-membered rings are necessary for positive curvature of the fullerenes, while the seven-membered rings for negative curvature. Experimentally, the negative curvature has been restricted so far to the joint between cone and tube in nanotubes and the spiral tubes. We have found a new type of multishell fullerenes with negative curvature which consist of three horns protrude into three-fold symmetric directions, referred as three-horned multishell fullerene (THF) in this report, using a high resolution transmission electron microscope (TEM). Here, we first describe the formation briefly and secondly concerned with procedure to determine the structure of the THF.