Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Industrial catalysts are often chemically and physically complex systems resulting from many years of technology, science, and art. Successful development of commercial catalysts requires talents of many disciplines including chemistry, chemical engineering, surface science, materials science, and physics. A better understanding of the relationship between catalyst structure and activity can provide a scientific prediction of catalytic properties. The insight gained from catalyst characterization can provide guidance for designing and synthesizing better commercial catalysts. Characterization of industrial catalysts is challenging and expensive; however, it can be highly rewarding in developing commercial catalysts used for manufacturing multibillion-dollar products.

The ultimate goal of catalyst characterization is to correlate the physical, chemical, mechanical, and electronic properties of a catalyst to its activity, selectivity, and stability. in industrial practice, however, because of the complexity of the catalysts, the time limit, and the available resources, the goal of characterizing industrial catalysts is often to elucidate the key performance indicators of a catalyst; these key performance indicators, such as the size and spatial distribution and the composition of the active components and promoters, can then be used to provide guidance for manufacturing better catalysts with desired properties.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Grain boundaries in fee metals with low stacking fault energy are known to undergo extended relaxations that can at times lead to a thin layer of a different structure. in Cu, for example, it has been found that Σ3{112}} boundaries relax into a 9R phase or even a bec phase. in this work, we have used high resolution electron microscopy to investigate the atomic structure of Σ99 grain boundaries in mazed bicrystal films of Au. On {001} Ge single crystal substrates, Au bicrystals can be grown in two equivalent {110} orientation variants, related to each other by a 90° rotation about the surface normal. There is equal probability to nucleate either orientation variant in early stages of film formation and since there is no reason for preferential growth, the morphology of the bicrystal film consists of many grains in only two orientations. All grain boundaries are of the type Σ99 and display tilt character.

Thin films 10-200nm thick were grown by physical vapor deposition on {001} Ge substrate at 280°C and followed by annealing at 200°C to relieve stresses.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

The mechanism for assembly of membrane lipid bilayers in vivo is generally considered to occur on existing membranes which act as templates for the assembly process. Not presently understood is the source of the membrane template. A thermodynamic theory describing a spontaneous process for assembly of unilamellar vesicles with properties of a critical state (1,2) has been tested in this study. The spontaneous formation of large unilamellar vesicles (LUV’s) from phospholipid components of cell membranes at a critical temperature T* has now been documented by cryo-electron microscope studies using aqueous dispersions of dimyrystoylphosphatidylcholine (T* = 29°C), and the total lipid extracts of E. coli membranes cultured at 32°C (T* = 32°C). The lipids were incubated at temperatures below, at and above the critical temperatures for LUV assembly. in conformity with thermodynamic theory, and other physical measurements that indicate unique bilayer properties exist at T* (3-5), LUV’s are seen to form only at T*.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

The Registration Desk at M&M 2012 is located on the Exhibit Level (one level down) inside the 3rd Street entrance to the Phoenix Convention Center North Building (See Map). Pick up your badge and Sunday Social Reception tickets at the Registration desk by 8:00 pm. The Sunday Social starts at 6:30 pm in the Convention Center Ballroom.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Advanced Ni8W/Ni12W/Ni8W alloy composite substrates used in YBCO-coated conductors with a strong cube texture and high yield strength have been fabricated, and a CeO2 buffer layer film was successfully deposited on the composite substrates. Through in situ tensile testing coupled with electron backscattered diffraction (EBSD) analysis, the stability of the cube texture of Ni8W/Ni12W/Ni8W alloy composite substrates has been investigated. The stress–strain curve shows that the yield strength (at 0.2% strain) of the composite substrates exceeds 250 Mpa. The orientation of grains and boundaries on the surface of the substrates was almost unchanged, while the strain exceeds 0.2%, which indicated that the composite substrates are adequate for depositing buffer layers and YBCO layers by the reel-to-reel process.

In this work, the correlation between composition and relative evaporation field was investigated by tracking the statistics of multi-hit detector events in atom probe tomography (APT). This approach is applied systematically to a GaN-based nitride heterostructure with five AlxGa1−xN layers of varying Al composition. The relative field evaporation and the percentage of multi-hit events were found to increase with higher Al concentration. Furthermore, the comparison of the relative evaporation fields of AlN with respect to the constituent ions is found to be less than GaN with respect to its constituent ions. Despite equivalent compositions between opposing interfaces of the same AlxGa1−xN interlayer, the rate of change in multiplicity exhibits a consistent asymmetric trend with a steeper slope across the AlxGa1−xN/GaN interface compared to the GaN/AlxGa1−xN interface. The AlxGa1−xN/GaN heterostructure serves as a test structure for exploring field evaporation and neighborhood chemistry, which can be applied to any material chemistry and particularly other nitride systems.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.