A technique based on neutron activation has been developed for an extremely high sensitivity analysis of trace elements in organic materials. Organic materials are sealed in plastic or high purity quartz and irradiated at the HFIR and MITR. The most volatile materials such as liquid scintillator (LS) are first preconcentrated by clean vacuum evaporation. Activities of interest are separated fro...

In 3 dimensions, it is possible to identify a wide range of systems such as (i) nanoparticles in solutions forming ferrofluids, (ii) percolating phases as found in manganites for example, (iii) magnetic domains or domain walls in crystals, (iv) long range helical structures as found in MnSi or BiFeO3 for example. These objects are ideally studied using Small Angle Neutron Scattering (SANS) whic...

We report a simple sonochemical method for the seeding and synthesis of Zinc Oxide nanowire arrays that can be formed on a number of substrates that are stable in alcohol and aqueous solution. Vertically aligned ZnO NWs were synthesized from a single solution at room-ambient via ultrasonic excitation. Prior to the NW growth, a ZnO seed layer was deposited using the same system with a different ...

Temperature and intensity dependence of steady state photoconductivity is studied in amorphous thin films of Ge22Se68Bi10 prepared by vacuum evaporation. Photoconductivity increases exponentially with temperature between 310 K and 410 K and no maxima is found in this temperature range. The ratio Iph/Id is about 6 at 310 K and decreases continuously as temperature is increased. Photoconductivity...

This paper describes the development of a new gas sensor device using some electroactive polymers in thin layers. The poly(fluoro-aluminium phthalocyanine) powder, (AlPcF)n, has been synthesized, then deposited by vacuum evaporation on alumina or silicon substrates in the form of thin films with control of the deposition rate. (AlPcF)n thin layers are doped by NO2 or O2 diluted at various conce...

As indicated in the opening article of this issue [11 thin epitaxial films of some III-Y semiconductors have properties which are important in high-frequency and optoelectronic applications. Such films can be prepared by conventional growth techniques such as liquid-phase epitaxy (LPE) or vapour-phase epitaxy (YPE). For particular applications it may be advantageous to use metal-organic vapour-...