Carbon nanotube (CNT)-reinforced aluminum composite powders were synthesized by cryogenic milling. The effects of different milling parameters and CNT contents on the structural characteristics and mechanical properties of the resulting composite powders were studied. Detailed information on powder morphology and the dispersion and structural integrity of the CNTs is crucial for many powder consolidation methods, particularly cold spray, which is increasingly utilized to fabricate metal-based nanocomposites. While all of the produced composite powders exhibited particle sizes suitable for spray applications, it was found that with increasing CNT content, the average particle size decreased and the size distribution became narrower. The dispersion of CNTs improved with milling time and helped to maintain a small Al grain size during cryogenic milling. Although extensive milling allowed for substantial grain size reduction, the process caused notable CNT degradation, leading to a deterioration of the mechanical properties of the resulting composite.

Microscopy & Microanalysis (M&M) 2012 celebrated the first 70 years of the Microscopy Society of America and energized attendees about present and future directions in our field. This joint meeting of the Microscopy Society of America, the Microanalysis Society, and the International Metallographic Society was held in Phoenix, Arizona, July 29–August 2, 2012. The conference had a robust technical program with 996 technical papers, 1,586 scientific attendees, and a total attendance of 2,648. Thirty-six different countries were represented among the attendees. The exhibition showcased 120 companies spread over 363 booths occupying 36,300 square feet of floor space.

Microscopy & Microanalysis 2012 will celebrate our past achievements, present our current research, and inspire us about the future of our field. The meeting will be held in Phoenix, Arizona from July 29–August 2, 2012.

In this article, we use simulated and experimental data to explore how three operator-controllable parameters—(1) signal level, (2) detector resolution, and (3) number of factors chosen for analysis—affect quantitative analyses of scanning transmission electron microscopy–energy dispersive X-ray spectroscopy spectrum images processed by principal component analysis (PCA). We find that improvements in both signal level and detector resolution improve the precision of quantitative analyses, but that signal level is the most important. We also find that if the rank of the PCA solution is not chosen properly, it may be possible to improperly fit the underlying data and degrade the accuracy of results. Additionally, precision is degraded in the case when too many factors are included in the model.

Erbium dihydride Er(H,D,T)2 is a fluorite structure rare-earth dihydride useful for the storage of hydrogen isotopes in the solid state. However, thermodynamic predictions indicate that erbium oxide formation will proceed readily during processing, which may detrimentally contaminate Er(H,D,T)2 films. In this work, transmission electron microscopy (TEM) techniques including energy-dispersive x-ray spectroscopy, energy-filtered TEM, selected area electron diffraction, and high-resolution TEM are used to examine the manifestation of oxygen contamination in ErD2 thin films. An oxide layer ∼30–130 nm thick was found on top of the underlying ErD2 film, and showed a cube-on-cube epitaxial orientation to the underlying ErD2. Electron diffraction confirmed the oxide layer to be Er2O3. While the majority of the film was observed to have the expected fluorite structure for ErD2, secondary diffraction spots suggested the possibility of either nanoscale oxide inclusions or hydrogen ordering. In situ heating experiments combined with electron diffraction ruled out the possibility of hydrogen ordering, so epitaxial oxide nanoinclusions within the ErD2 matrix are hypothesized. TEM techniques were applied to examine this oxide nanoinclusion hypothesis.

Lead loss during processing of solution-derived Pb(Zr,Ti)O3 (PZT)-based thin-films can result in the formation of a Pb-deficient, nonferroelectric fluorite phase that is detrimental to dielectric properties. It has recently been shown that this nonferroelectric fluorite phase can be converted to the desired perovskite phase by postcrystallization treatment. Here, quantitative standard-based energy-dispersive x-ray spectrometry (EDS) in a scanning transmission electron microscope (STEM) is used to study cation distribution before and after this fluorite-to-perovskite transformation. Single-phase perovskite PbZr0.53Ti0.47O3 (PZT 53/47) and Pb0.88La0.12Zr0.68Ti0.29O3 (PLZT 12/70/30) specimens that underwent this treatment were found to be chemically indistinguishable from the perovskite present in the multiphase specimens prior to the fluorite-to-perovskite transformation. Significant Zr–Ti segregation is found in PLZT 12/70/30, but not in PZT 53/47. Slight La-segregation was seen in rapidly crystallized PLZT, but not in more slowly crystallized PLZT.

Chemical solution deposition has been used to fabricate continuous ultrathin lead lanthanum zirconate titanate (PLZT) films as thin as 20 nm. Further, multilayer capacitor structures with as many as 10 dielectric layers have been fabricated from these ultrathin PLZT films by alternating spin-coated dielectric layers with sputtered platinum electrodes. Integrating a photolithographically defined wet etch step to the fabrication process enabled the production of functional multilayer stacks with capacitance values exceeding 600 nF. Such ultrathin multilayer capacitors offer tremendous advantages for further miniaturization of integrated passive components.

A diffusion multiple is an assembly of three or more different metal blocks, in intimate interfacial contact, that is subjected to a high temperature to allow thermal interdiffusion. The power of using a diffusion multiple approach in the efficient mapping of phase diagrams and materials properties for multicomponent alloy systems is illustrated in this article using several examples. It is now possible to map phase diagrams and materials properties at an efficiency some 3 orders of magnitude higher than the conventional one-alloy-at-a-time approach. With this high efficiency, many critical materials data that otherwise would be too time-consuming and expensive to acquire can be obtained and employed to accelerate our understanding of a system's materials physics and chemistry. It is postulated that coupling the diffusion multiple approach with the CALPHAD (calculation of phase diagrams) method will have a significant impact on the computational design of materials.

The potential utility of FIB for routine (and novel) applications has come to forefront recently due to advances in ion optics which now allow formation of focused ion probe of better than ∼10-20 nm containing current density exceeding several A/cm2, with a liquid metal source (typically Gallium). The small ion probe size, coupled with shallow sputtering depth - yet high sputtering yield of ions, has opened several opportunities in machining, lithography and ion-assisted deposition[ 1-3] These developments, including automation, multi-specimen stages, cross-compatible specimen holders for FIB/TEM/SEM, use of in-situ electron beam (so-called dual beam), coupled with innovations such as the “lift-off process[4], have provided an invaluable set of tools for microelectronic defect characterization. However, re-deposition (contamination), ion implantation/damage especially for desirable thinner sections (<∼50 nm) remain major concerns for further applications.

While much of the excitement in TEM community for FIB is due to thin foil specimen preparation (especially in microelectronics),

The validity of controlling interfacial toughness in reaction-formed composites was explored using solid-state reaction processing and microanalysis techniques. A variety of rare-earth oxides was added to a yttrium aluminum garnet (YAG)/alumina powder mixture and then melted in air. Some melts retained the crystallography and microstructure of the pure, binary YAG–alumina eutectic. Using scanning transmission electron microscopy in conjunction with energy dispersive X-ray spectroscopy, rare-earth ions were observed both to segregate to the YAG/alumina interface and to form a third phase. Some evidence of increased crack deflection at these interfaces was observed via indentation fracture.