Last November's Microscopy Today was our first special issue to focus on a single microscopy topic (scanning probe microscopy). The present issue on surface analysis is the first to have a guest editor, Vincent Smentkowski. Vincent brought me the idea of a special issue on surface analysis, and I was pleased to help him bring this topic to our readers. Many journals publish highly technical special issues, but that is not the goal here. These articles on surface analysis techniques are aimed at the general microscopist. Each article provides a brief introduction to a technique, discusses the method's capabilities, and gives a few applications.

In the animal kingdom, eyes come in a relatively small variety of functional forms. When a new optical system is found, it usually is a variation of a known form. It is very rare to discover a novel form of an eye. Such a sensational discovery has been made by Annette Stowasser, Alexandra Rapaport, John Layne, Randy Morgan, and Elke Buschbeck. Using two different experimental approaches, they demonstrated an eye with a truly bifocal lens, something that has only been suggested for certain long-extinct trilobites

The surface, or topmost layers of a material, is the region that is in contact with the environment. The composition and chemistry of the surface often can be drastically different from that of the bulk. For many materials systems (catalysts, coatings, biomedical devices, etc.), the surface chemistry and/or properties determine the device performance. Adhesion, delamination, staining, and corrosion are among the important surface phenomena that need to be understood in industrial settings. Over the past forty years, a number of surface analysis techniques have been commercialized to characterize the composition and microstructure of the surface. The most commonly used techniques are summarized in this issue of Microscopy Today.

Over the past decade, the field of nanotechnology has expanded, and the most heavily used nanoscale characterization/imaging techniques have been scanning probe microscopy (SPM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Although these high-resolution imaging techniques help visualize nanostructures, it is essential to understand the chemical nature of these materials and their growth mechanisms. Surface modifications in the first few nanometers can alter the bulk properties of these nanostructures, and conventional characterization techniques, including energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) associated with SEM and TEM are not suited to detecting these surface modifications except in special, favorable specimens. A modern state-of-the-art scanning Auger electron spectroscopy (AES) instrument provides valuable elemental and chemical characterization of nanostructures with a lateral spatial resolution better than 10 nm and a depth resolution of a few nm. In this article we review the technique of scanning AES and highlight its unique analytical capabilities in the areas of nanotechnology, metallurgy, and semiconductors.

Our common introduction to the laws of chemistry is rooted in the bulk, steady-state phenomena of solution and gas chemistries. This eases the introduction of the mathematical structure required to explain our macroscopic measurements. We come to understand that chemical change is driven by local gradients in the bulk and that gradients are steepest where properties change most rapidly. This is exactly what happens at material interfaces, where the mathematics get complicated, chasing infinities, and approximations often have to suffice. This confirms what we intuitively knew from everyday observation, that chemical dynamics take place at the interfaces between materials. The interfaces are where the action is.

In order to meet the challenges of more economical and environmentally benign energy production, a new generation of complex materials and devices are being developed, including thin film solar cells, fuel cells, and batteries. In all stages of development there is a requirement for materials characterization and analysis, from the initial development stages through to testing of the finished product. Most materials need to be analyzed for compositional homogeneity across surfaces and also for confirmation of film thickness and layer chemistry.

The properties of many modern products are not only governed by their surface morphology and structure but also by their surface chemistry. For example, in some cases a contamination of less than a monolayer of molecules can be responsible for the failure of a coating with all its consequences (aesthetics, protection, life time, and so on). Other areas affected by surface chemistry are adhesion, staining, corrosion, and so on. Thus, powerful analytical techniques for the identification, as well as the localization and quantification, of substances on a surface or at the interface between different layers are of increasing importance for fast and efficient failure analysis. However, surface analysis is not only limited to failure analysis but can be also used in research and development of, for example, methods of surface modification on the molecular level as well as in production and quality control, such as the evaluation of cleaning procedures.

Low-energy ion scattering (LEIS) has gained new capabilities and now provides high-end instrumentation for real-world surface analytical applications. Although the technique has been available for some decades, recent developments in instrumentation make the unique capabilities of LEIS accessible for everyday applications. Special ion energy analyzer designs allow LEIS to be used for non-destructive quantitative analysis of the elemental composition of the outermost atomic layer with high sensitivity and high mass resolution. At the same time, the composition of the first 10 nm of sub-surface material is also assessed. Applications are very broad, ranging from catalysts to various thin films to polymers.

Gunshot residue (GSR) is typically found on the hands or clothing of persons who have been in the environment of a discharging firearm, but it may also be found on objects in the vicinity of the discharge. Computer-controlled scanning electron microscopy (CCSEM) is the method preferred by the forensic community for the automated analysis of GSR. GSR samples are therefore typically collected from a crime suspect's hands and/or clothing using SEM sample stubs coated with a conductive adhesive. The three major components in modern firearm cartridge primers are lead styphanate (initiator), antimony sulfide (fuel), and barium nitrate (oxidizer). GSR consists of the products of combustion of these primer materials. Large populations of particles in the size range of ~1–10 μm are rapidly screened by energy-dispersive X-ray spectroscopy (EDS) for the presence of combinations of Pb, Sb, and Ba. When combinations of these three elements are detected, the particles are flagged as potential GSR particulate. Flagged particles with significant Pb/Sb/Ba compositions are subsequently relocated for a live identification and a positive confirmation of GSR. Positive particles are classified as being either “characteristic of GSR” (that is, all three key elements are present) or “consistent with GSR” (that is, any two of the key elements are present) based on the particle composition and morphology. Classification is based on the presence of the constituent elements and is not dependant on the element amounts. If a particle does not meet the proper compositional or morphological criteria, it is rejected as GSR. However, CCSEM generally does not provide information regarding the population of particles much less than 1 μm or the surface chemistry of the GSR particles. This article examines the fine fraction of GSR particles with high-resolution electron microscopy and complements the microscopy data with surface chemistry information from X-ray photoelectron spectroscopy (XPS).

Bugscope is a free online microscopy outreach program that offers K–12 classrooms anywhere in the world the ability to remotely operate a high-resolution scanning electron microscope, collect images of insects and other similar arthropods, and chat simultaneously with a team of scientists. It was conceived and implemented in the late 1990s when K–12 schools were beginning to gain broadband Internet access, many as a result of the Telecommunications Act of 1996. One of several projects that took advantage of this opportunity to use the Internet to bring the laboratory into the classroom, Bugscope began as an NSF grant to purchase a field-emission scanning electron microscope and develop sophisticated client and server software to control it via a standard web browser. Inspired by the success of and lessons learned from the Chickscope remote magnetic resonance imaging project and from having successfully established remote web-based control of a transmission electron microscope, Clint Potter and Bridget Carragher created the Bugscope project with the goal of developing a remote microscopy educational outreach project that would be sustainable over the long term. This goal led to two significant design decisions. First, the software involved in setting up and running the live outreach sessions was purpose-built to ensure that only one staff member, if necessary, would be required at the instrument (as opposed to Chickscope, which required staff at the remote location as well as at the instrument). Second, students from a local high school would be employed as a renewable resource to help with pre-session sample preparation and to participate in live chat, answering questions from the remote classrooms. Although we now operate with permanent staff at the instrument, these efficiencies in the original concept/design have allowed Bugscope to operate continuously since March 1999, long after the original funding was exhausted.

Leonhard Euler is best known as a prolific mathematician, but he also made notable contributions in optics and astronomy. He was born in Basel, Switzerland on April 15, 1707, the son of Paul Euler, a Protestant minister, and Margaret Brucker, the daughter of a Protestant minister. Accordingly, Leonhard Euler was raised to follow suit and join the ministry, but his father had sparked his interest in mathematics at a young age, and this interest was further cultivated at the University of Basel, which he entered at the age of fourteen. His prodigious ability in the field impressed renowned mathematics professor Johann Bernoulli, who allowed Euler to visit with him on Sundays to discuss any difficulties the young scholar had in understanding the advanced books on mathematics that he had recommended. Nevertheless, even in 1723, Euler still appeared to be set on a course that would lead him to the church, having gained his Master's degree in philosophy and embarked on studies of theology. Soon after, however, with the help of Bernoulli, Euler convinced his father to permit him to study mathematics instead.

Selected postings from the Microscopy Listserver from November 1, 2010 to December 31, 2010. Complete listings and subscription information can be obtained at http://www.microscopy.com. Postings may have been edited to conserve space or for clarity.

With the advent of the computer age and in particular, the Internet, information sources have multiplied. However, the need for information verification has never been greater. In a day when anyone can easily produce a website, blog, or tweet, you can't believe what you read or see just because it's “published.” Scientific data and analysis require peer review, and peer-reviewed data need a home. Equally important, for every piece of data in a peer-reviewed publication, there are usually many pieces that provided essential support for the conclusions of the study but could not be included due to space limitations. This is especially true of image data, which are necessarily gigabyte-hungry.