The Cold Neutron Depth Profiling (CNDP) instrument at the NIST Cold Neutron Research Facility (CNRF) is now operational. The neutron beam originates from a 16 L D2O ice cold source and passes through a filter of 135 mm of single crystal sapphire. The neutron energy spectrum may be described by a 65 K Maxwellian distribution. The sample chamber configuration allows for remote controlled scanning of 150 × 150 mm sample areas including the varying of both sample and detector angle. The improved sensitivity over the current thermal depth profiling instrument has permitted the first nondestructive measurements of 17O profiles. This paper describes the CNDP instrument, illustrates the neutron depth profiling (NDP) technique with examples, and gives a separate bibliography of NDP publications.

The effects of exchange current density, Tafel slope, system resistance, electrode area, light intensity, and solar cell efficiency were systematically decoupled at the converter-assisted photovoltaic–water electrolysis system. This allows key determinants of overall efficiency to be identified. On the basis of this model, 26.5% single-junction GaAs solar cell was combined with a membrane-electrode-assembled electrolysis cell (EC) using the dc/dc converting technology. As a result, we have achieved a solar-to-hydrogen conversion efficiency of 20.6% on a prototype scale and demonstrated light intensity tracking optimization to maintain high efficiency. We believe that this study will provide design principles for combining solar cells, ECs, and new catalysts and can be generalized to other solar conversion chemical devices while minimizing their power loss during the conversion of electrical energy into fuel.

Magnesium oxide (MgO) precursors were prepared by the sol-gel method using magnesium acetate. The reaction products and intermediates obtained during the sol-gel processing of magnesium acetate under various conditions were analyzed thermally and spectroscopically. No organic groups were detected by infrared spectroscopy after heat treating the reaction products at 400 °C. A large exothermic differential thermal analysis peak below 400 °C demonstrated the oxidation of organic moieties in each product. It was found that the presence of an acid catalyst was crucial during the sol-gel processing of magnesium acetate to produce sols suitable for depositing MgO films. The MgO films fabricated on Si(111) substrates using the precursor sol showed (200) orientation regardless of the presence of surface oxides on the substrates.

Films of manganese doped zinc silicate have been deposited using the charged liquid cluster beam technique. The deposition conditions were found to have a large impact on the morphology and photoluminescence intensity of these films. The photoluminescence intensity was maximized at a manganese content near δ=0.04 in (Zn1−δMnδ)2SiO4. No phases other than zinc silicate were detectable with manganese contents up to δ=0.08.

Bis(alkyl 3-oxobutanoato)copper(II) compounds were synthesized and utilized to deposit copper films, where alkyl = methyl, ethyl, 2-methoxyethyl, tert-butyl, and benzyl. Copper films were deposited at temperatures as low as 160 °C. They showed conformal coverage on patterned substrates with holes of diameter as small as 0.35 μm and aspect ratio as high as 3. Average grain size of the deposited copper films depended on substrate temperature. The alkyl 3-oxobutanoate ligands liberated from the precursors analyzed to be intact during the deposition processes.