The performance metric of greatest interest to the user of a focused ion beam (FIB) system is generally its resolution. Because of the difficulty in defining and measuring the resolution of a FIB system directly, its performance is often assessed using a method related to the beam quality instead. This consists of the measurement of the rise distance of the beam current as the beam passes across an edge, which, for low currents where spherical aberration can be neglected, is closely related to the full width at half maximum (FWHM) of the current density of the ion beam. The edge, also known as the “knife edge,” corresponds to a sharp discontinuity in a specimen, as can be practically found on the surface of a graphite specimen. Because the rise distance can be used to obtain an idea of the dimension of the waist of a beam, it is, perhaps, an indication of the quality of an instrument. Because the rise distance depends on the quality of an edge, it is sometimes called edge sharpness. This concept bears similarities with the image sharpness method developed to assess the performance of SEMs, usually on gold nanoparticles on carbon specimen. Rise distance is actually a convolution of the current density distribution with the properties of the knife edge and depends strongly on the spatial distribution of the secondary electron yield of the edge. By using the rise distance, different systems can be compared in a quantitative way. To compare instruments, the identical specimen must be used and the measurements must be done in an identical way. This article discusses the method and some pitfalls in its application.

Since its introduction in 2007, DTSA-II has been adopted by numerous researchers, and it has been integrated into numerous educational programs. This is the first of a series of articles in Microscopy Today that will appear in the upcoming months to provide an introduction to use of the product. These articles also will provide details of how DTSA-II can be used to implement best practices for microanalysis in your laboratory or in your teaching environment. These articles will demonstrate how to form the most accurate type of spectrum quantification—standards-base quantification—as well as how to use simulation to optimize various types of measurement problems. They will focus on using DTSA-II to understand the physical process including the interaction of energetic electrons with your sample and the propagation of x-rays through matter and to the detector.

Since the creation of the Joint Committee on Powder Diffraction Standards (JCPDS) over sixty years ago, the Powder Diffraction File (PDF) has been the key source of standard powder diffraction data for identification and analysis of materials of all types, from natural minerals and high-tech ceramics to metals and alloys and pharmaceuticals. Although this editorially reviewed database has been the mainstay for diffraction pattern reference for the x-ray powder diffraction community, recent developments provide information and tools for electron diffraction. In recent years, the International Centre for Diffraction Data (ICDD, formerly JCPDS) has transformed the flat-file format of the PDF to a more flexible relational database (RDB) format. The PDF has been greatly expanded to include calculated patterns from multiple collaborating databases, including the Inorganic Crystal Structure Database (FIZ Karlsruhe, Germany), the Linus Pauling File (MPDS, Vitznau, Switzerland), and the Cambridge Structural Database (CCDC, Cambridge, United Kingdom). A significant portion of its entries include atomic coordinates and a specific database dedicated to organic phases exists. All new entries for the ICDD databases undergo over 100 quality checks before inclusion, and a quality mark is assigned for each entry that passes.

Quantifying an X-ray spectrum is the process of converting a measured spectrum into an estimate of the composition of the material from which the spectrum was collected. In a certain sense, interpreting X-ray spectra is very simple. A spectrum from even the most complex material can be thought of as a sum of spectra from the constituent elements (see Figure 1). To first approximation, if you know the spectrum for the constituent pure elements, you can estimate the spectrum for the complex material. Regardless of the software vendor or the name of the algorithm, this is the basis for quantification of all X-ray spectra.

The previous article in this series introduced DTSA-II and provided some background information including how to configure DTSA-II for your x-ray detector and how to read spectra from disk. This article presents more basic background material. It discusses how to display and perform basic manipulations on spectra including reading the contextual properties of spectra, visualizing spectra, labeling characteristic x-ray lines, and exporting the results as publication-quality graphics. You are encouraged to follow along using DTSA-II and example spectra, which may be downloaded for free from http://www.cstl.nist.gov/div837/837.02/epq/dtsa2/index.html or equivalently http://goo.gl/MI1Ku. With this background material, we will be ready to consider more sophisticated tasks like spectrum quantification and simulation in upcoming articles.

Multiple techniques now exist for the investigation of nanoscale magnetic properties, extending from Lorentz microscopy and magneto-optical imaging (MOKE) to scanning probe microscopy approaches (see Figure 1 for an overview). Among the latter, the most widely used techniques offering both high spatial and high magnetic-field resolution are magnetic force microscopy (MFM) and scanning Hall probe microscopy (SHPM). Both techniques are well known for their versatility and ease of use and can be further adapted for operation in cryogenic conditions. This property is crucial for all areas of research where high magnetic fields are required and where the influence of thermal energy/broadening needs to be suppressed. For example, much of today's fundamental research on superconductivity, spintronics, and magnetic data storage is taking place at low temperatures.

The night before I'm scheduled to volunteer on the Biobus, Dr. Ben Dubin-Thaler—the bus's owner and educational director—calls to give me directions: Take the 5 train to the Bronx, get off at the second-to-last stop. Make two rights and then a left on Baychester Avenue. Walk to John Philip Sousa Middle School. “We'll be parked out front,” Dubin-Thaler tells me. I hesitate, imagining picking my way through a sea of frenzied children and identical school buses. “You'll see us,” says Dubin-Thaler.

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.

Microscopy & Microanalysis (M&M) is the annual meeting for the Microscopy Society of America, the Microbeam Analysis Society, and the International Metallographic Society, Inc. This is the premier conference for microscopists working in the physical, life, and analytical sciences.

The development of large-area silicon drift detectors (SDDs) provides a significant improvement in X-ray micro-analysis, especially in scanning electron microscopes (SEMs) and electron microprobes, where high incident probe currents are possible. The resultant improved detection limits and/or speed of elemental mapping and analysis make the SDD the detector of choice for microanalysis. With the larger geometric collection efficiency and faster response times of these detectors, the higher input count rates can place significant demands on the performance and speed of the signal processing electronics.

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.

Four successive generations of the Becquerel family were educated at the prestigious French scientific institution of higher learning, the École Polytechnique, and became physics professors at the French Museum of Natural History. Alexandre Edmond Becquerel was the son of Antoine César (1788– 1878), discoverer of piezoelectricity; father of Antoine Henri (1852– 1908), who discovered radioactivity; and the grandfather of Jean Antoine (1878–1953), who is best known for his work on relativity and the discovery of polarization rotation in the presence of a magnetic field. Though all of these notable scientists carried out a variety of experiments related to optics, it was Alexandre Edmond Becquerel who made the greatest contributions to the field.

Microscopists are looking at smaller features every day, and the potential to see artifacts that degrade or obscure these small features has never been greater. Because many current microscopy techniques are conducted in vacuum environments, residual gaseous components in the vacuum chamber may have substantial effects on the data collected. This brief review will describe some approaches to keep the quality of data collected in electron and ion-beam microscopes at the highest possible levels. In short, we will attempt to “keep it clean.”

Metallic and non-metallic nanoparticles (NPs), ranging in size from 1–200 nm, have unique functional properties that differ from their bulk materials and their component atoms or molecules. These unique properties have driven the demand for nano-sized materials and new methods to synthesize NPs, which are used in drug delivery systems, bio-imaging agents, catalysts, photonics, and optical devices. Inorganic NPs can be synthesized with a variety of methods that impart size, shape, and other structural properties. Cobalt-based NPs, for instance, display unique size and shape-dependent magnetic properties, while the band gap, UV blocking properties and stability of zinc oxide (ZnO) NPs enable new applications in products ranging from cosmetics to solar cell power.

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.

In his 2011 State of the Union address, President Barack Obama echoed the sentiments of this nation's leaders for the past twenty years when he stated, “Nations like China and India realized…they could compete in this new world. So they started educating their children earlier and longer, with greater emphasis on math and science. They're investing in research and new technologies…. Maintaining our leadership in research and technology is crucial to America's success. But if we want to win the future—if we want innovation to produce jobs in America and not overseas—then we also have to win the race to educate our kids.” The Bergen County Academies (BCA) in Hackensack, NJ, is attempting to do just that: invest in research and technology at the high school level in order to expose students to real world opportunities and applications they will experience in the future.

In Microscopy Today, January 2011, Piper and Chmela published an article called “Advanced Techniques for Observation and Photomicrography of Subcellular Structures in Diatom Shells.” This paper clamors for some comments of a fundamental nature.