Practical Scanning Electron Microscopy

In the spring of 1963, a well-known research institute made a market survey to assess how many scanning electron microscopes might be sold in the United States. They predicted that three to five might be sold in the first year a commercial SEM was available, and that ten instruments would saturate the marketplace. In 1964, the Cambridge Instruments Stereoscan was introduced into the United States and, in the following decade, over 1200 scanning electron microscopes were sold in the U. S. alone, representing an investment conservatively estimated at $50,000- $100,000 each. Why were the market surveyers wrongil Perhaps because they asked the wrong persons, such as electron microscopists who were using the highly developed transmission electron microscopes of the day, with resolutions from 5-10 A. These scientists could see little application for a microscope that was useful for looking at surfaces with a resolution of only (then) about 200 A. Since that time, many scientists have learned to appreciate that information content in an image may be of more importance than resolution per se. The SEM, with its large depth of field and easily that often require little or no sample prepara interpreted images of samples tion for viewing, is capable of providing significant information about rough samples at magnifications ranging from 50 X to 100,000 X. This range overlaps considerably with the light microscope at the low end, and with the electron microscope at the high end.

This book has evolved by processes of selection and expansion from its predecessor, Practical Scanning Electron Microscopy (PSEM), published by Plenum Press in 1975. The interaction of the authors with students at the Short Course on Scanning Electron Microscopy and X-Ray Microanalysis held annually at Lehigh University has helped greatly in developing this textbook. The material has been chosen to provide a student with a general introduction to the techniques of scanning electron microscopy and x-ray microanalysis suitable for application in such fields as biology, geology, solid state physics, and materials science. Following the format of PSEM, this book gives the student a basic knowledge of (1) the user-controlled functions of the electron optics of the scanning electron microscope and electron microprobe, (2) the characteristics of electron-beam-sample inter actions, (3) image formation and interpretation, (4) x-ray spectrometry, and (5) quantitative x-ray microanalysis. Each of these topics has been updated and in most cases expanded over the material presented in PSEM in order to give the reader sufficient coverage to understand these topics and apply the information in the laboratory. Throughout the text, we have attempted to emphasize practical aspects of the techniques, describing those instru ment parameters which the microscopist can and must manipulate to obtain optimum information from the specimen. Certain areas in particular have been expanded in response to their increasing importance in the SEM field. Thus energy-dispersive x-ray spectrometry, which has undergone a tremendous surge in growth, is treated in substantial detail.

For this new edition, the chapters on photography and the electron microscope have been completely rewritten and two new chapters have been added--on immuno electron microscopy using colloidal gold and on useful specialized techniques.

This book has its origins in the intensive short courses on scanning elec tron microscopy and x-ray microanalysis which have been taught annually at Lehigh University since 1972. In order to provide a textbook containing the materials presented in the original course, the lecturers collaborated to write the book Practical Scanning Electron Microscopy (PSEM), which was published by Plenum Press in 1975. The course con tinued to evolve and expand in the ensuing years, until the volume of material to be covered necessitated the development of separate intro ductory and advanced courses. In 1981 the lecturers undertook the project of rewriting the original textbook, producing the volume Scan ning Electron Microscopy and X-Ray Microanalysis (SEMXM). This vol ume contained substantial expansions of the treatment of such basic material as electron optics, image formation, energy-dispersive x-ray spectrometry, and qualitative and quantitative analysis. At the same time, a number of chapters, which had been included in the PSEM vol ume, including those on magnetic contrast and electron channeling con trast, had to be dropped for reasons of space. Moreover, these topics had naturally evolved into the basis of the advanced course. In addition, the evolution of the SEM and microanalysis fields had resulted in the devel opment of new topics, such as digital image processing, which by their nature became topics in the advanced course.

This text provides students as well as practitioners with a comprehensive introduction to the field of scanning electron microscopy (SEM) and X-ray microanalysis. The authors emphasize the practical aspects of the techniques described. Topics discussed include user-controlled functions of scanning electron microscopes and x-ray spectrometers and the use of x-rays for qualitative and quantitative analysis. Separate chapters cover SEM sample preparation methods for hard materials, polymers, and biological specimens. In addition techniques for the elimination of charging in non-conducting specimens are detailed.

This book was developed with the goal of providing an easily understood text for those users of the scanning electron microscope (SEM) who have little or no background in the area. The SEM is routinely used to study the surface structure and chemistry of a wide range of biological and synthetic materials at the micrometer to nanometer scale. Ease-of-use, typically facile sample preparation, and straightforward image interpretation, combined with high resolution, high depth of field, and the ability to undertake microchemical and crystallographic analysis, has made scanning electron microscopy one of the most powerful and versatile techniques for characterization today. Indeed, the SEM is a vital tool for the characterization of nanostructured materials and the development of nanotechnology. However, its wide use by professionals with diverse technical backgrounds—including life science, materials science, engineering, forensics, mineralogy, etc., and in various sectors of government, industry, and academia—emphasizes the need for an introductory text providing the basics of effective SEM imaging.A Beginners’ Guide to Scanning Electron Microscopy explains instrumentation, operation, image interpretation and sample preparation in a wide ranging yet succinct and practical text, treating the essential theory of specimen-beam interaction and image formation in a manner that can be effortlessly comprehended by the novice SEM user. This book provides a concise and accessible introduction to the essentials of SEM includes a large number of illustrations specifically chosen to aid readers' understanding of key concepts highlights recent advances in instrumentation, imaging and sample preparation techniques offers examples drawn from a variety of applications that appeal to professionals from diverse backgrounds.

Offers a simple starting point to VPSEM, especially for new users, technicians and students containing clear, concise explanations Crucially, the principles and applications outlined in this book are completely generic: i.e. applicable to all types of VPSEM, irrespective of manufacturer. Information presented will enable reader to turn principles into practice Published in association with the Royal Microscopical Society (RMS) -www.rms.org.uk