Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

Volume 10 of Microscopy and Microanalysis marks this journal's tenth year. The stated aim of the journal remains to provide a forum for original research papers dealing with new microscopy and microanalysis techniques and their applications. Papers are indexed in several databases including MEDLINE(PubMed) and Chemical Abstracts. Also provided are book reviews and a comprehensive calendar of microscopy events. The journal title is owned by the Microscopy Society of America, and the publisher is Cambridge University Press. The journal now ranks among the top microscopy journals in the world. This achievement is directly attributable to the efforts of its many editors, editorial board members, authors, and reviewers. Particularly notable is the work of my two predecessors, Jean-Paul Revel and Dale Johnson. I thank you all.

It is estimated that more than half of the human population, plus a much greater number of domestic and wild animals, suffer from parasitic infections. The magnitude of the problem can be illustrated by estimates of more than 100 million cases and 1 million deaths each year from malaria alone.

This special issue of Microscopy and Microanalysis contains 17 articles from a topical conference on microbeam characterization of nonconductive materials. The conference was held at the Department of Mining, Metals, and Materials Engineering of McGill University in Montreal on August 2–3, 2002, as the pre-meeting congress prior to the Microscopy & Microanalysis 2002 meeting in Quebec City, Canada.

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Extended abstract of a paper presented at the Pre-Meeting Congress: Materials Research in an Aberration-Free Environment, at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, July 31 and August 1, 2004.

This issue is dedicated to Regents' Professor John Maxwell Cowley, FRS, in recognition of his lifelong contributions to electron microscopy, diffraction, and crystallography. This collection of 22 peer-reviewed articles is based on presentations made at the international workshop entitled “Recent Developments and Applications of Atomic Resolution Electron Microscopy and Spectroscopy—A Silver Jubilee.” The workshop was held in the historic Old Main building on the campus of Arizona State University in early January 2003 and was attended by about 150 people. It celebrated the 25th anniversary of the Center for High Resolution Electron Microscopy, which was founded by John Cowley, and also served as an occasion to honor him on his 80th birthday. Keynote speakers included Sumio Iijima, discoverer of the carbon nanotube; Mikail Roco, senior advisor on nanotechnology for the National Science Foundation; and John Cowley himself, whose lecture addressed innovative ideas for achieving sub-Ångstrom resolution without requiring aberration correction.

A recent article in these pages compares STEM images with an image obtained with the One-Ångstrom Microscope (OÅM) at Lawrence Berkeley National Laboratory (LBNL). Although the experimental work is of excellent quality, Diebold et al. (2003) offer an incorrect explanation of the image formation process in the high-resolution transmission electron microscope. It is important that this misinterpretation be corrected before it comes to be accepted as factual by other scientists who are not expert in the field of high-resolution transmission electron microscopy.

While searching the internet for “nanotechnology,” I was not surprised to find many definitions. Two of these are as follows: (1) nanotechnology is the development and use of devices that have a size of only a few nanometers; and (2) nanotechnology can best be considered as a “catch-all” description of activities at the level of atoms and molecules that have applications in the real world. While nanotechnology is usually focused on the building of structures at the atomic scale, the characterization of such structures should also be considered as nanotechnology. At the Microscopy and Microanalysis 2002 Meeting in Quebec City, together with Tom Kelly and Mike Thompson, I organized a symposium entitled “Advances in Nanoscale Technology.” The response to this symposium was impressive, with 32 contributed and 7 invited presentations. Some of these presentations concentrated on atom probe field ion microscopy and form the basis for the invited contributions in this special issue of Microscopy and Microanalysis.

This work reviews recent research on the design and control of interfaces in engineering nanomaterials. Four case studies are presented that demonstrate the power of a multimodal approach to the characterization of different types of interfaces. We have used a combination of conventional, high resolution, and analytical transmission electron microscopy, microbeam electron diffraction, and three-dimensional atom probe to study polymer–clay nanocomposites, turbine rotor steels used for power generation, multicomponent aluminum alloys, and nanocrystalline magnetic materials.

The main purpose of the article by A.C. Diebold and coworkers (2003) is to propose a robust method for determination of gate oxide thickness. O'Keefe objects to a statement in this paper that “Lattice images do NOT depict the projected atom columns; instead, they are interference patterns of the directly transmitted beam with diffracted beams.”

The symposia for Microscopy and Microanalysis (M&M) 2004 have a strong emphasis on scientific applications, in contrast to a focus during the past few years on particular techniques. The Biological (B) and Physical (P) Sciences symposia feature a variety of important target scientific areas. The Advances in Instrumentation and Techniques (A) symposia tend to be aimed at cross-cutting methods that bring representatives of different communities together, for example, biological and physical scientists, X-ray and electron scatterers, “real world” microscopists in different applications fields, or practitioners of complementary microscopy and microanalysis methods that address a common class of problems. The program focus on scientific applications is balanced by a strong PreMeeting Congress, “Materials Research in an Aberration-Free Environment,” which promises to present the cutting edge of instrumentation and techniques, with an eye toward the future. The current state-of-the-art of a number of microscopy techniques is also covered in Tutorials during the meeting. Other programming venues include a variety of Sunday Short Courses, the Presidential Happenings, the IMS Sorby Award lecture, the Technologists' Forum, and “Ask the Experts.” Publicly accessible programming include an art exhibit featuring the works of David Scharf and admission to the Exhibit Hall; these may be of interest to family members of meeting registrants. Similar to last year, symposia will be highlighted with watermarks to provide “at a glance” identification of broad categories of programming. This year, practical problem solving (“RealWorld”) and nanotechnology (“Nano”) are used typically to denote microscopy and microanalysis studies that contribute understanding to translate technology into products that promise to drive today's and tomorrow's economies, respectively.

A novel imaging mode for high-resolution transmission electron microscopy is described. It is based on the adjustment of a negative value of the spherical aberration CS of the objective lens of a transmission electron microscope equipped with a multipole aberration corrector system. Negative spherical aberration applied together with an overfocus yields high-resolution images with bright-atom contrast. Compared to all kinds of images taken in conventional transmission electron microscopes, where the then unavoidable positive spherical aberration is combined with an underfocus, the contrast is dramatically increased. This effect can only be understood on the basis of a full nonlinear imaging theory. Calculations show that the nonlinear contrast contributions diminish the image contrast relative to the linear image for a positive-CS setting whereas they reinforce the image contrast relative to the linear image for a negative-CS setting. The application of the new mode to the imaging of oxygen in SrTiO3 and YBa2Cu3O7 demonstrates the benefit to materials science investigations. It allows us to image directly, without further image processing, strongly scattering heavy-atom columns together with weakly scattering light-atom columns.

The physical mechanisms involved in electron irradiation of insulating specimens are investigated by combining some simple considerations of solid-state physics (trapping mechanisms of electrons and secondary electron emission) with basic equations of electrostatics. To facilitate the understanding of the involved mechanisms only widely irradiated samples having a uniform distribution of trapping sites are considered. This starting hypothesis allows development of simple models for the trapped charge distributions in ground-coated specimens as investigated in electron probe microanalysis (EPMA) as well as for the bare specimens investigated in scanning electron microscopy (SEM) and environmental SEM (ESEM). Governed by self-regulation processes, the evolution of the electric parameters during the irradiation are also considered for the first time and practical consequences in EPMA, SEM, and ESEM are deduced. In particular, the widespread idea that the noncharging condition of SEM is obtained at a critical energy E2 (where δ + η = 1 with δ and η yields obtained in noncharging experiments) is critically discussed.

Giardia lamblia is a flagellated protozoan of great medical and biological importance. It is the causative agent of giardiasis, one of the most prevalent diarrheal disease both in developed and third-world countries. Morphological studies have shown that G. lamblia does not present structures such as peroxisomes, mitochondria, and a well-elaborated Golgi complex. In this review, special emphasis is given to the contribution made by various microscopic techniques to a better knowledge of the biology of the protozoan. The application of video microscopy, immunofluorescence confocal laser scanning microscopy, and several techniques associated with transmission electron microscopy (thin section, enzyme cytochemistry, freeze-fracture, deep-etching, fracture-flip) to the study of the cell surface, peripheral vesicles, endoplasmic reticulum–Golgi complex system, and of the encystation vesicles found in trophozoites and during the process of trophozoite-cyst transformation are discussed.

Extended abstract of a paper presented at the Pre-Meeting Congress: Materials Research in an Aberration-Free Environment, at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, July 31 and August 1, 2004.

A small probe centered on an atomic column excites the bound and unbound states of the two-dimensional projected potential of the column. It has been argued that, even when several states are excited, only the 1s state is sufficiently localized to contribute a signal to the high-angle detector. This article shows that non-1s states do make a significant contribution for certain incident probe profiles. The contribution of the 1s state to the thermal diffuse scattering is calculated directly. Sub-Ångstrom probes formed by Cs-corrected lenses excite predominantly the 1s state and contributions from other states are not very large. For probes of lower resolution when non-1s states are important, the integrated electron intensity at the column provides a better estimate of image intensity.

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

Extended abstract of a paper presented at the Pre-Meeting Congress: Materials Research in an Aberration-Free Environment, at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, July 31 and August 1, 2004.

Improvements in instrumentation and image processing techniques mean that methods involving reconstruction of focal or beam-tilt series of images are now realizing the promise they have long offered. This indirect approach recovers both the phase and the modulus of the specimen exit plane wave function and can extend the interpretable resolution. However, such reconstructions require the a posteriori determination of the objective lens aberrations, including the actual beam tilt, defocus, and twofold and threefold astigmatism. In this review, we outline the theory behind exit plane wavefunction reconstruction and describe methods for the accurate and automated determination of the required coefficients of the wave aberration function. Finally, recent applications of indirect reconstruction in the structural analysis of complex oxides are presented.