An array of very uniform cylindrical nanopores with a pore diameter as small as 25 nm has been fabricated in an ultrathin micromachined silicon nitride membrane using focused ion beam (FIB) etching. The pore size of this nanosieve membrane was further reduced to below 10 nm by coating it with another silicon nitride layer. This nanosieve membrane possesses adequate mechanical strength up to several bars of transmembrane pressure, and it can withstand high temperatures up to 900 °C. In addition, it is inert to many aggressive chemicals such as hot concentrated potassium hydroxide (KOH), piranha (H 2 SO 4 + H 2 O 2 ), and nitric acid (HNO 3 ).

We present a monolithic device obtained by carving a cantilever on the top of a single-mode optical fiber. We show that the vertical position of the cantilever can be determined with accuracy comparable to atomic force microscopes and other commonly used scientific instruments. The device does not require any alignment procedure and can be used in critical environments as well as in standard applications.

Focused ion beam (FIB) milling is receiving increasing attention for nanostructuring in silicon (Si). These structures can for example be used for photonic crystal structures in a silicon-on-insulator (SOI) configuration or for moulds which can have various applications in combination with imprint technologies. However, FIB fabrication of submicrometre holes having perfectly vertical sidewalls is still challenging due to the redeposition effect in Si. In this study we show how the scan routine of the ion beam can be used as a sidewall optimization parameter. The experiments have been performed in Si and SOI. Furthermore, we show that sidewall angles as small as 1.5 • are possible in Si membranes using a spiral scan method. We investigate the effect of the dose, loop number and dwell time on the sidewall angle, interhole milling and total milling depth by studying the milling of single and multiple holes into a crystal. We show that the sidewall angles can be as small as 5 • in (bulk) Si and SOI when applying a larger dose. Finally, we found that a relatively large dwell time of 1 ms and a small loop number is favourable for obtaining vertical sidewalls. By comparing the results with those obtained by others, we conclude that the number of loops at a fixed dose per hole is the parameter that determines the sidewall angle and not the dwell time by itself.

In a recent paper (Iannuzzi et al 2006 Monolithic fiber-top sensor for critical environments and standard applications Appl. Phys. Lett. 88 053501) we have presented the principle of the fiber-top position sensor, having a monolytical structure carved out of a single-mode optical fiber. The device alleviates sensing in a critical environment via interferometric readout, and because of its monolithic construction, facilitates plug-and-play utilization without alignment. In this paper we describe the fabrication method of a similar device which, however, was also equipped with a pyramidal tip on the top of the cantilever, an important detail for future implementation in scanning probe microscopy. A silicon surface was then periodically put in contact and moved out of contact with the device. The output signal resembles force curves that can be similarly obtained with atomic force microscopes.

Super-duplex stainless steels are recently developed high alloyed stainless steels that combine good mechanical properties with excellent corrosion resistance. Because of a high content of chromium and molybdenum, these alloys are susceptible to o-phase precipitation during short exposure to temperatures between 650 and 950°C. The effect of 800°C aging on o-phase formation and on the mechanical properties of a super-duplex stainless steel have been reported previously by the authorsJ This investigation concerns the effect of o-phase precipitation at 800°C on the corrosion behaviour in seawater and comprises anodic polarization scans and potentiostatic crevice corrosion tests. A serious deterioration of the corrosion resistance is found after aging times longer than 7 min, resulting in a drop of both the critical crevice corrosion temperature (CCT) and the breakdown potential (Ebd). The initiation of localized corrosion takes place next to the o-phase, in the newly formed secondary austenite (Y2).

Fibre-top cantilevers are a new generation of miniaturized devices obtained by carving tiny mechanical beams directly on the cleaved edge of an optical fibre. The light coupled from the other side of the fibre allows measurements of the position of the cantilever with sub-nanometre accuracy. The monolithic structure of the device, the absence of electronic contacts on the sensing head, and the simplicity of the working principle offer unprecedented opportunities for the development of scientific instruments for both standard applications and utilization beyond research laboratories. In this paper we review the results that our group has obtained over the last year in the development of this technology. We describe the working principle and the fabrication procedure, and we present a series of proof-of-concept experiments that demonstrate that fibre-top cantilevers can be used both for atomic force microscopy and for the detection of chemical species.

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With focused ion-beam irradiation it is possible to engineer the anisotropy of magnetic films on nanometer length scales. We used this technique to write square lattices of artificial domain-wall pinning centers in a perpendicular anisotropy GdFe film displaying a well-defined stripe domain pattern. We observe a clear lock in of the intrinsic meandering stripe pattern to the pinning lattices, resulting in highly ordered domain patterns. We find that at remanence the dots pin the domain walls, while in perpendicular applied magnetic fields they host the down domains.