While the idea of electron holography has been around for over 50 years, the technology necessary to establish a window to the phase world is only now becoming available. This is the first report of an all digital system for displaying the image phase continuously and live, instead of looking at one frame at a time after initiation of the reconstruction procedure. The technical requirements, including the necessary image processing steps which differ from the standard reconstruction procedure for single frame holograms, will be discussed, and current time demands for image acquisition and the different elements of image processing will be laid out. The modified requirements for continuous, live processing will be discussed in detail, and images obtained in the live mode will be shown.

Zeolites are crystalline aluminosilicates with frameworks built from corner-sharing TO4- tetrahedra(where T is Si or Al but can also be substituted with P, Ga, Ge, etc.) to produce channels or cavities of molecular dimensions. Owing to these characteristic features, zeolites have attracted much attention not only for catalytic applications but also as containers of confined materials. In most circumstances zeolites can only be synthesized as fine powders, ca. 1 μm, and the additional presence of defects or intergrowths makes structure solution difficult. HREM is therefore one of the most important tools for the investigation of such structures and the early work of Thomas and his group in Cambridge were dedicated to developing such techniques. The advantage of HREM has been subsequently demonstrated especially for characterizing and determining fine structures, e.g. (i) zeolite intergrowths structures such as ERI/OFF and FAU/EMT, (ii) enantiomeric intergrowths of structural units in ETS-10 and structural solution, (iii) surface structures and growth units and (iv) size of clusters and their registry with the framework structures.

Valence electron energy-loss (VEEL) spectroscopy was performed on six ceramic materials in a dedicated scanning transmission electron microscope (STEM). Quantitative analysis of these data is described yielding access to the complex optical properties and the electronic structure of the materials. Comparisons are made on the basis of the interband transition strength describing transitions between occupied states in the valence band and empty states in the conduction band. This proves that the quantitative analysis of VEEL data is a competitive and complementary method to be considered when investigating the electronic structure of materials. Possibilities for improvement and extension of the analysis are discussed extensively.

Despite the great potential of fluorescence microscopy, its application to date has largely been in the study of biological specimens. It will be shown that conventional fluorescence microscopy provides an invaluable tool with which to study the photophysics of polymer-supported luminescence-based oxygen sensors. The design of the imaging system, the measurement methods, and the data analysis used in the investigation of sensor systems are described. Fluorescence microscopic images of sensor films in which microheterogeneous regions exhibiting enhanced luminescence intensity and poorer oxygen quenching relative to the bulk response are shown. This is the first direct evidence that sensor molecules in various domains of the polymer support can exhibit different oxygen quenching properties. It will be shown that μ- and nano-crystallization of the sensor molecule are the probable source of both the observed heterogeneous microscopic responses and the microscopic and macroscopic nonlinear Stern-Volmer plots. The implications of these results in the rational design of luminescence-based oxygen sensors are discussed.

Transmission electron microscope samples of two types of metal matrix composites were prepared using both traditional thinning methods and the more novel focused ion beam miller. Electropolishing methods were able to produce, very rapidly, thin foils where the matrix was electron transparent, but the ceramic reinforcement particles remained unthinned. Thus, it was not possible in these foils to study either the matrix-reinforcement interface or the microstructure of the reinforcement particles themselves. In contrast, both phases in the composites prepared using the focused ion beam miller thinned uniformly. The interfaces in these materials were clearly visible and the ceramic reinforcement was electron transparent. However, microstructural artifacts associated with ion beam damage were also observed. The extent of these artifacts and methods of minimizing their effect were dependent on both the materials and the milling conditions used.

The atomic force microscope (AFM) has previously been applied to the measurement of surfaceforces (including adhesion and friction) and to the investigation of material properties, such as hardness. Herewe describe the modification of a commercial AFM that enables the stiffness of interaction between surfacesto be measured concurrently with the surface forces. The stiffness is described by the rheological phasedifference between the response of the AFM tip to a driving oscillation of the substrate. We present theinteraction between silica surfaces bearing adsorbed polymer, however, the principles could be applied to a widevariety of materials including biological samples.

The development and makeup of a real-time full remote control system for the University of Michigan, Department of Materials Science and Engineering Teaching SEM is described. The instrument was initially controlled via the campus local area Ethernet network and cable TV network. The latest implementation employs Fast Ethernet, Asynchronous Transfer Mode (ATM) networks, and moving picture experts group (MPEG) video encoding to effect the remote control via the computer network alone. Remote control demonstrations from Washington, DC, Dearborn, MI, and Emerson School, Ann Arbor, MI are described.

A focused ion beam (FIB) technique was applied to cross-sectional specimen preparation to observe an interface between a plasma sprayed coating and an aluminum (Al) substrate by transmission electron microscopy (TEM). The surface of the sprayed coating film has a roughness of several tens of microns. Sputter rates for the coating film and the substrate are greatly different. The rough surface and the difference in sputter rate cause problems in making TEM specimens with smooth side walls. The top surface of the coating film was planerized by the FIB before fabricating the TEM specimen. The interfaces were investigated by TEM and energy-dispersive X-ray (EDX) analysis. The TEM observation revealed that there is a 10 nm thick amorphous layer at the interface between the coating film and substrate. The coating film consists of two kinds of sublayers with bright and dark contrast. The bright contrast sublayers were amorphous layers with thickness of 2~10 nm. The Al/Fe X-ray intensity ratio was larger in bright contrast sublayers than that in dark contrast sublayers.

Magnetotactic bacteria from aquatic environments were analyzed with the electron spectroscopic imaging technique. Rod-shaped bacteria and cocci were present in most of the samples observed. Magnetotactic multicellular aggregates were also observed at some of the sampling sites. The use of electron spectroscopic imaging allowed the observation of magnetosomes inside magnetotactic microorganisms with exceptional clarity. The number, size, and morphology of magnetosomes, as well as their ultrastructural spatial disposition inside the bacterial cell, could be directly observed and associated with the disposition of flagella of the respective cells.This allowed us to examine the structural relationships between magnetosomes and flagella, which are important components in the mechanisms of magnetotaxis. In disrupted magnetotactic multicellular aggregates, connections between cells were also visualized. We believe this technique will be useful in studying not only magnetotactic bacteria but also other uncultured microorganisms from natural environments.

Technologies such as compact disc (CD) manufacturing, hologram embossing, and security printingrely on the reproduction of micro-patterns generated on surfaces by optical or electron-beam lithographicwriting onto electron-beam or photoresists. The periodicity of such patterns varies from sub-micron to severalmicrons, with depths up to 0.5 μm. The scanning probe microscope (SPM) is becoming a routine tool foranalysis of these micro-patterns, to check on depths and lateral dimensions of features. Direct scanning ofresist-covered plates is now possible, without damage, using resonant low-contact force SPM with etched siliconcantilevers. Metal shims produced from the master resist plates can also be scanned and checked for defectsprior to production of embossed foils. The present article discusses examples of the use of a Digital Instruments3100 microscope in analysis of production electron-beam lithography plates with a 0.5 μm resist thickness. Wealso examine features of nickel replicas (father and mother shims) produced by electroforming from theoriginal plate. With SPM measurements of the development profile of a particular plate, corrections can bemade to exposures and development times during production to correct errors. An example is given of sucha feedback process.

Nanomaterials have attracted a great deal of research interest recently. The small size of nanostructures constrains the applications of well-established testing and measurement techniques, thus new methods and approaches must be developed for quantitative measurement of the properties of individual nanostructures. This article reports our progress in using in situ transmission electron microscopy to measure the electrical, mechanical, and field-emission properties of individual carbon nanotubes whose microstructure is well-characterized. The bending modulus of a single carbon nanotube has been measured by an electric field-induced resonance effect. A nanobalance technique is demonstrated that can be applied to measure the mass of a tiny particle as light as 22 fg (1 fg = 10−15 g), the smallest balance in the world. Quantum conductance was observed in defect-free nanotubes, which led to the transport of a superhigh current density at room temperature without heat dissipation. Finally, the field-emission properties of a single carbon nanotube are observed, and the field-induced structural damage is reported.

The engineering of a new generation of advanced materials based on nanoparticles demands the fabrication of self-assembled arrays of passivated metal, oxide and semiconductor clusters (1 -). In particular the case of self-assembled gold clusters passivated with an organic molecule has attracted the attention of several researchers (2-3). Because its unique properties gold metal is a leading candidate for the fabrication of single electron tunneling devices.

Passivated gold nanoclusters were produced using the method developed by Brust et.al. (4) with the modifications of Whetten et.al (5) n-alkylthiol molecules were used as passivating agent. Carbon chains from C=4 to C=18 were used. It was found that C=12 dodecanethiol was optimum for forming ordered arrays of the clusters. To produce the superlattice crystallization a toluene vapor atmosphere was used. The passivated clusters were deposited on a copper electron microscope grid covered with carbon.

A fiber-optic based spectral cathodoluminescence (CL) system has been successfully installed on a variable pressure “environmental” scanning electron microscope (ESEM). The fine size of the fiber (50 μm) has been found to require careful alignment. To provide this alignment, a simple X–Y translator has been used. The aligned fiber exhibits high efficiency and the system has recorded spectra at up to 3 million “counts” per sec on strongly cathodoluminescent doped yttrium aluminium garnet (YAG) samples, at 30 kV and ˜3 nA. A resolution of 3 nm [full width half maximum (FWHM)] at 621 nm has been measured from a red laser diode spectrum, on the ESEM column. A range of uncoated materials has been measured to characterize the CL system; these materials ranged from strongly luminescent YAG to weakly luminescent polymers. Wellcharacterized doped zircons have also been investigated. These data suggest that the previously reported intrinsic peak from zircon is a consequence of high-beam currents.

The current status and general applicability of scanning electron microscopy (SEM) at low voltages is reviewed for both imaging (low voltage scanning electron microscopy, LVSEM) and chemical microanalysis (low voltage energy-dispersive X-ray spectrometry, LVEDX). With improved instrument performance low beam energies continue to have the expected advantages for the secondary electron imaging of low atomic number (Z) and electrically non-conducting samples. They also provide general improvements in the veracity of surface topographic analysis with conducting samples of all Z and at both low and high magnifications. In new experiments the backscattered electron (BSE) signal retains monotonic Z dependence to low voltages (<1 kV). This is contrary to long standing results in the prior literature and opens up fast chemical mapping with low dose and very high (nm-scale) spatial resolution. Similarly, energy-dispersive X-ray chemical microanalysis of bulk samples is extended to submicron, and in some cases to <0.1 μm, spatial resolution in three dimensions at voltages <5 kV. In favorable cases, such as the analysis of carbon overlayers at 1.5 kV, the thickness sensitivity for surface layers is extended to <2 nm, but the integrity of the sample surface is then of concern. At low beam energies (E0) the penetration range into the sample, and hence the X-ray escape path length out of it, is systematically restricted (R = F(E05/3)), with advantages for the accuracy or elimination of complex analysis-by-analysis matrix corrections for absorption (A) and fluorescence (F). The Z terms become more sensitive to E0 but they require only one-time calibrations for each element. The new approach is to make the physics of the beam–specimen interactions the primary factor and to design enabling instrumentation accordingly.

Reliability of thermal barrier coatings (TBC) hinges on the adhesion of a thermally grown oxide scale to an insulative ceramic topcoat and an underlying metallic bondcoat. The width of the scale and its interfaces makes transmission electron microscopy (TEM) an appropriate tool for its analysis. However, specimen preparation has proven to be a challenging obstacle leading to a dearth of TEM research on TBCs. A new approach to cross-section TBC TEM specimen preparation is described. The principal advantages of this technique are reproducibility, reduced specimen damage, and time savings resulting from decreased ion milling. This technique has been successfully applied to numerous TBC specimens with various thermal histories.

Charge contrast images (CCI) of synthetic gibbsite obtained on an environmental scanning electron microscope gives information on the crystallization process. Furthermore, X-ray mapping of the same grains shows that impurities are localized during the initial stages of growth and that the resulting composition images have features similar to these observed in CCI. This suggests a possible correlation between impurity distributions and the emission detected during CCI. X-ray line profiles, simulating the spatial distribution of impurities derived from the Monte Carlo program CASINO, have been compared with experimental line profiles and give an estimate of the localization. The model suggests that a main impurity, Ca, is depleted from the solution within approximately 3–4 μm of growth.

Atomic force microscope images of aluminium sheet are used to calculate the mean roughness Ra andthe root mean square roughness Rq for different directions ([theta]) across the samples. The angle determined valuesof Ra([theta] and Rq([theta]) are significantly lower in the rolling direction than in any other direction. The resultsprovide a clear demonstration of the vector nature of surface roughness. Local features in an angle determinedRq([theta]) profile are also compared with the positions of peaks and valleys in the matching topographical crosssectionof the surface running at right angles to [theta]. It is further found that the distribution of z heights for animaged sample is usually not Gaussian in shape unless the z heights are measured about mean lines constructedacross the surface parallel with the rolling direction. The results are relevant for controlling lubricationperformance in the aluminium rolling process.

We describe a hidden parameter inferencing algorithm for deducing the length, width, and vibration profile from images of thermally excited single-wall carbon nanotubes. With accurate estimates of these parameters, the Young’s modulus can be deduced. The algorithm is sensitive to shot noise in the image, primarily because of the low nanotube image contrast. Noise causes the nanotube length and width to be overestimated, and the vibration amplitude to be underestimated. After correcting for shot noise, we infer an average value of the Young’s modulus of 〈Y〉= 1.20±0.20 TPa, which is larger than the currently accepted value for graphite.