High quality single crystal silicon-germanium-on-insulator has the potential to facilitate the next generation of photonic and electronic devices. Using a rapid melt growth technique we engineer tailored single crystal silicon-germanium-on-insulator structures with near constant composition over large areas. The proposed structures avoid the problem of laterally graded SiGe compositions, caused by preferential Si rich solid formation, encountered in straight SiGe wires by providing radiating elements distributed along the structures. This method enables the fabrication of multiple single crystal silicon-germanium-on-insulator layers of different compositions, on the same Si wafer, using only a single deposition process and a single anneal process, simply by modifying the structural design and/or the anneal temperature. This facilitates a host of device designs, within a relatively simple growth environment, as compared to the complexities of other methods, and also offers flexibility in device designs within that growth environment.

Reactions of Ta(NMe2)5 and n-propylamine are shown to be an effective system for sol-gel processing of Ta3N5. Ordered macroporous films of Ta3N5 on silica substrates have been prepared by infiltration of such a sol into close-packed sacrificial templates of cross-linked 500 nm polystyrene spheres followed by pyrolysis under ammonia to remove the template and crystallize the Ta3N5. Templates with long-range order were produced by controlled humidity evaporation. Pyrolysis of a sol-infiltrated template at 600 °C removes the polystyrene but does not crystallize Ta3N5, and X-ray diffraction shows nanocrystalline TaN plus amorphous material. Heating at 700 °C crystallizes Ta3N5 while retaining a high degree of pore ordering, whereas at 800 °C porous films with a complete loss of order are obtained.

To investigate the role of intermetallic particles in the localised corrosion of AA7075‐T6, three particles were monitored over 16 h immersion in 3.5 wt% KCl solution. These were examined using Auger electron spectroscopy, energy dispersive X‐ray spectroscopy, scanning Kelvin probe force microscopy and focused ion beam‐scanning electron microscopy. Despite similar Volta potential measurements, the corrosion microchemistry varied significantly with composition. A Al7Cu2Fe intermetallic resulted in trenching while a (Al,Cu)6(Fe,Cu) intermetallic showed crevice corrosion and sub‐surface intergranular corrosion and a Al12Fe3Si intermetallic appeared to be galvanically inactive but showed crevice formation at the matrix interface and sub‐surface intergranular corrosion.

The effect on the Volta potential, measured from second phase particles in beryllium, by the thin layer of hydrocarbon contamination pyrolized onto the surface under the action of an electron beam during secondary electron imaging has been investigated. Despite being only a few nanometers thick, this contamination has a significant influence on the Volta potential of second phase particles of interest. This work shows that such contamination can have a substantial effect on the measured potential of particles, acting to increase or decrease the Volta potential difference compared to the metallic matrix.

This work provides new insight and evidence that challenges and extends the accepted view of the oxidation behaviour of Kovar (ASTM-15). Specimens of 2 mm diameter Kovar wire were oxidised in air at 700 or 800°C for 10 min. The resulting oxide layers were analysed by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, scanning transmission electron microscopy and Raman spectroscopy. Oxide layers of approximately 2 and 4 lm thickness were formed at 700 and 800°C, respectively. These were found to contain iron, cobalt and traces of nickel. The combination of analysis techniques revealed that the oxide contains Fe 2 O 3 in addition to (Fe, Co, Ni) 3 O 4 , a spinel oxide, in contrast to the combinations of Fe 3 O 4 , Fe 2 O 3 and FeO that are typically reported. The oxide layer was found to be complex, consisting of multiple layers with different compositions, which is overlooked in the existing literature.Keywords Raman spectroscopy Á Spinels Á X-ray photoelectron spectroscopy (XPS) Á Scanning electron microscopy (SEM) Á Glass-to-metal seal