We investigated the growth of carbon nanotubes (CNTs) directly on stainless steel substrates. The CNTs were grown using a two-step process: oxidation of the stainless steel surface and CNT growth. The samples were oxidized in an 800 degrees C furnace fed with a flow of air for 4 min. CNTs were grown by switching the flow to ethylene, which both reduces the oxide and initializes CNT growth. The time of CNT growth was varied to understand how the samples evolved over time. To better understand the growth mechanisms, we isolated crosssections of the CNT-substrate interface using a focused ion beam. These cross-sections were investigated with transmission electron microscopy and energy dispersive X-ray spectroscopy. CNTs were seen to grow from ironrich nanoparticles embedded in the oxide layer. The oxide layer was also seen to lose iron over time, suggesting that these iron nanoparticles were reduced out of the oxide. The base particles were embedded in the oxide layer, leaving cavities when the CNTs were removed. The diameters of the nanotubes were also seen to grow over time as a result of carbon infiltration. The effects of the embedded particle and infiltration quickly isolate the catalyst, leading to short CNTs (1-10 mu m).

Journal Article Mechanisms for Chemical Vapor Deposition Carbon Nanotube Growth by Surface Modification of 316L Stainless Steel Get access Joshua Hancock, Joshua Hancock Department of Physics, Brigham Young University, Provo, UT, United States Search for other works by this author on: Oxford Academic Google Scholar Felipe Rivera, Felipe Rivera Department of Physics, Brigham Young University, Provo, UT, United StatesElectron Microscopy Facility, Brigham Young University, Provo, UT, United States Search for other works by this author on: Oxford Academic Google Scholar Brian Jensen, Brian Jensen Department of Mechanical Engineering, Brigham Young University, Provo, UT, United States Search for other works by this author on: Oxford Academic Google Scholar Richard Vanfleet Richard Vanfleet Department of Physics, Brigham Young University, Provo, UT, United States Corresponding author: richard_vanfleet@byu.edu Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 29, Issue Supplement_1, 1 August 2023, Pages 759–761, https://doi.org/10.1093/micmic/ozad067.375 Published: 22 July 2023

Journal Article Simultaneous HAADF & EELS Data Acquisition for Relative Quantification of Temperature and Thickness Effects on Thermal Diffuse Scattering in STEM Get access Paul S Minson, Paul S Minson Brigham Young University, Electron Microscopy Facility, Provo, UT, United StatesBrigham Young University, Physics and Astronomy, Provo, UT, United States Corresponding author: paul.minson@byu.edu Search for other works by this author on: Oxford Academic Google Scholar Felipe Rivera, Felipe Rivera Brigham Young University, Electron Microscopy Facility, Provo, UT, United StatesBrigham Young University, Physics and Astronomy, Provo, UT, United States Search for other works by this author on: Oxford Academic Google Scholar Richard Vanfleet Richard Vanfleet Brigham Young University, Physics and Astronomy, Provo, UT, United States Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 29, Issue Supplement_1, 1 August 2023, Pages 358–360, https://doi.org/10.1093/micmic/ozad067.167 Published: 22 July 2023

Profilicollis rancoensis n. sp. is the tenth species of Profilicollis Meyer, 1931 which includes 9 other species mostly known from marine decapod crabs and shore birds. Cystacanths of P. rancoensis are described from the dominant freshwater crab Aegla abtao in Ranco Lake, Chile and are morphologically distinguished from cystacanths of the 9 other species based on a combination of 4 characters. These are body size, number of proboscis hook rows, number of hooks per row, and length of the largest anterior 2–4 hooks. Male and female cystacanths of P. rancoensis are 2.10–3.33 mm long having an ovoid proboscis with 14 rows of 6–7 hooks per row, with the largest anterior 2–4 hooks being 105–110 micrometers long; the anterior trunk has many small spines in 70–80 concentric rings, each with 50–60 spines around them; hook roots are simple, directed posteriorly, about as long as the blades anteriorly with unremarkable anterior manubria; the cephalic ganglion are in mid-receptacle just anterior to the level of the anterior trunk; the lemnisci are long and slender; the testes are in the anterior trunk, posterior trunk, or one in each; the primordia of 2 tubular cement glands are evident; strong bundles of fibers link the anterior and posterior trunk; and the posterior trunk has a corrugated surface cuticula. Molecular analysis (COI and 18S) sequences coincided with the morphology and support its taxonomy. The phylogenetic profile revealed that P. rancoensis n. sp. fell into the Profilicollis clade. Both sequences showed low genetic variation, and three different haplotypes were found. The new species was more closely related to P. botulus (Van Cleave, 1916) Witenberg, 1932 than to other Profilicollis species.

Journal Article Application of Focused Ion Beam and Scanning Electron Microscopy for the Sectioning and Study of Acanthocephalan Hooks Get access Solinus Farrer, Solinus Farrer Department of Biology, Brigham Young University, Provo, UT, United States Search for other works by this author on: Oxford Academic Google Scholar Michael Standing, Michael Standing Electron Microscopy Facility, Brigham Young University, Provo, UT, United States Search for other works by this author on: Oxford Academic Google Scholar Felipe Rivera, Felipe Rivera Electron Microscopy Facility, Brigham Young University, Provo, UT, United States Corresponding author: felipe.rivera@byu.edu Search for other works by this author on: Oxford Academic Google Scholar Omar Amin Omar Amin Institute of Parasitic Diseases, Scottsdale, AZ, United States Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 29, Issue Supplement_1, 1 August 2023, Pages 1113–1115, https://doi.org/10.1093/micmic/ozad067.571 Published: 22 July 2023

In the last two decades, advances in the dark field detectors and microscopes of scanning transmission electron microscopy (STEM) have inspired a resurgence of interest in quantitative STEM analysis. One promising avenue is the use of STEM as a nanothermometric probe. In this application, thermal diffuse scattering, captured by a CCD camera or an annular dark field detector, acts as an indirect measurement of the specimen temperature. One challenge with taking such a measurement is achieving adequate sensitivity to quantify a change in scattered electron signal on the order of 1% or less of the full electron beam. Another difficulty is decoupling the thermal effect on electron scattering from scattering changes due to differing specimen thicknesses and materials. To address these issues, we have developed a method using STEM, combined with electron energy loss spectroscopy (EELS), to produce a material-specific calibration curve. On silicon, across the range 89 K to 294 K, we measured a monotonically increasing HAADF signal ranging from 4.0% to 4.4% of the direct beam intensity at a thickness-to-mean-free-path ratio of 0.5. This yielded a calibration curve of temperature versus full-beam-normalized, thickness-normalized HAADF signal. The method enables thermal measurements on a specimen of varying local thickness at a spatial resolution of a few nanometers. We demonstrated the potential of the technique for testing electron scattering models by applying single-electron scattering theory to the data collected to extract a measurement of the mean atomic vibration amplitude in silicon at 294 K. The measured value, 0.00738 +/- 0.00002 nm, agrees well with reported measurement using X-rays.

The morphology of cystacanths and adults of Profilicollis altmani (Perry, 1942) Van Cleave, 1947 (Polymorphidae) were studied from the Pacific mole crab Emerita analoga (Stimpson) (Crustacea, Hippidae) and Belcher's gull Larus belcheri (Vigors) (Aves, Laridae), respectively, in Peru. Comparative morphometrics with accounts of other populations of P. altmani from elsewhere off the Pacific and Atlantic coasts of North and South America revealed marked intraspecific population variations. We report scanning electron micrographs (SEM) of new features, not before noted or captured in line drawings by earlier observers. We further present microscope images that reveal internal details not previously reported or possible to see with SEM. Energy dispersive X-ray analysis (EDXA) revealed unusual patterns in the chemistry of proboscis hooks especially the high sulfur and diminished phosphorous and calcium in hook tips and low sulfur and high levels of phosphorous and calcium at mid hooks. The size and shape of all hooks of the cystacanths are reported for the first time. Histopathological studies in L. belcheri from Peru are also included. Cystacanths of P. altmani from California were also analyzed for molecular patterns and compared with other sequences reported from other locations. The molecular data and the analysis of our new sequences of cytochrome oxidase I (COI) showed that haplotypes of P. altmani had low genetic variation; the species is not geographically structured, and within its clade no monophyletic group is formed.

Metal–Organic Frameworks (MOFs) are an important material class that are increasingly relevant for many fields including catalysis. Templated catalysts derived from MOF thin-films have tunable properties based on preparation environment.

Ultrafast pump-probe spectroscopy shows that the photo-induced monoclinic-to-rutile phase transformation in vanadium dioxide thin films occurs in 40±0.5 ps independent of nanograin morphology, because substrate-induced strain leads to common families of grain orientations.

Transmission electron microscopy (TEM) and focused ion beam (FIB) are proven tools to produce site-specific samples in which to study devices from initial processing to causes for failure, as well as investigating the quality, defects, interface layers, etc. However, the use of polymer substrates presents new challenges, in the preparation of suitable site-specific TEM samples, which include sample warping, heating, charging, and melting. In addition to current options that address some of these problems such as cryo FIB, we add an alternative method and FIB sample geometry that address these challenges and produce viable samples suitable for TEM elemental analysis. The key feature to this approach is a larger than usual lift-out block into which small viewing windows are thinned. Significant largely unthinned regions of the block are left between and at the base of the thinned windows. These large unthinned regions supply structural support and thermal reservoirs during the thinning process. As proof-of-concept of this sample preparation method, we also present TEM elemental analysis of various thin metallic films deposited on patterned polycarbonate, lacquer, and poly-di-methyl-siloxane substrates where the pattern (from low-to high-aspect ratio) is preserved.

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