The electronic microcircuit industry has placed severe demands on metal suppliers to provide metals of the highest reproducible purity attainable as a result of the constant quest for the true values of physical and chemical properties of metals. This article describes the commonly used methods for ultrapurification of metals produced by electrolytic processes, including fractional crystallization, zone refining, vacuum melting, distillation, chemical vapor deposition, and solid state refining techniques. In addition, it describes the trace element analysis and resistance-ratio test methods used to characterize purity. Tables list the values for resistance ratios of zone-refined metals and their corresponding chemical compositions, and provide an example of the detection of impurities to concentrations in the parts per billion range, utilizing a combination of the glow discharge mass spectroscopy method and Leco combustion methods.

Neutron activation analysis (NAA) is a highly sensitive and accurate method of assaying bulk materials for trace levels of many elements. This article provides a detailed account on several types of NAA, namely, nondestructive and radiochemical thermal neutron activation, delayed neutron counting, epithermal and 14-MeV fast neutron activation, and prompt gamma activation analysis. It also includes application examples, explaining where and how each method is used and the types of elements on which they are effective.

Ultraviolet/visible (UV/VIS) absorption spectroscopy is a powerful yet cost-effective tool that is widely used to identify organic compounds and to measure the concentration of principal and trace constituents in liquid, gas, and solid test samples. This article emphasizes the quantitative analysis of elements in metals and metal-bearing ores. The instrumentation required for such applications consists of a light source, a filter or wavelength selector, and some type of visual or automated sensing mechanism. The article examines common sensing options and provides helpful information on how to set up and run a variety of UV/VIS absorption tests.

This article provides a brief account of glow discharge mass spectrometry (GDMS) for direct determination of trace elements in solid samples and for fast depth profiling in a great variety of innovative materials. It begins by describing the general principles of GDMS. This is followed by a discussion on the various components of a GDMS system as well as commercial GDMS instruments. A description of processes involved in specimen preparation and cleaning in GDMS is then presented. Various problems pertinent to multielemental calibrations in GDMS are discussed along with measures to overcome them. The article further provides information on the processes involved in the analytical setup of parameters in GDMS, covering the steps involved in the analysis of GDMS data. It ends with a section on the application and interpretation of GDMS in the metals industry.

During the melting and solidification of cast irons, certain trace (minor) elements may unintentionally accumulate to an extent that they have a detrimental effect on the microstructure of castings. This article discusses the residual elements, trace elements, and tramp elements in cast irons. Elements that influence the matrix structure of cast irons are commonly classified as ferrite-promoting elements or pearlite-promoting elements. The article describes the effects of minor elements on microstructure and properties of cast irons. It discusses the use of a combination of tools to control the effects of minor elements on the structure and properties of cast irons. The article concludes with information on allowable levels of trace and tramp elements in cast irons.

This article discusses the basic principles of inductively coupled plasma mass spectrometry (ICP-MS), covering different instruments used for performing ICP-MS analysis. The instruments covered include the sample-introduction system, ICP ion source, mass analyzer, and ion detector. Emphasis is placed on ICP-MS applications in the semiconductor, photovoltaic, materials science, and other electronics and high-technology areas.

This article provides a detailed account of the concepts and applications of neutron activation analysis (NAA), covering the basic principles and neutron reactions of NAA as well as calibration methods used for NAA. The discussion also covers the factors pertinent to analytical sensitivity achievable with NAA, common neutron sources, sample-handling technique, and automated systems of NAA. The categories of NAA covered are instrumental neutron activation analysis, epithermal neutron activation analysis, radiochemical neutron activation analysis, 14 MeV fast neutron activation analysis, delayed neutron activation analysis, and prompt gamma activation analysis.

Atomic absorption spectrometry (AAS) is generally used for measuring relatively low concentrations of approximately 70 metallic or semimetallic elements in solution samples. This article describes several features that are common to three techniques, namely, AAS, atomic emission spectrometry (AES), and atomic fluorescence spectrometry (AFS). It discusses the reasons for the extreme differences in AAS sensitivities that affect AFS and AES. The article provides information on the advantages and disadvantages of the Smith/Hieftje system and two types of background correction systems, namely, the continuum-source background correction and Zeeman background correction. It also provides a list of applications of conventional AAS equipment, which includes most of the types of samples brought to laboratories for elemental analyses.

This article is a detailed account of the principles of electron-excited X-ray microanalysis. It begins by discussing the physical basis of electron-excited X-ray microanalysis and the advantages and limitations of energy dispersive spectrometry (EDS) and wavelength dispersive spectrometry for electron probe microanalysis. Key concepts for performing qualitative analysis and quantitative analysis by electron-excited X-ray spectrometry are then presented. Several sources that lead to measurement uncertainties in the k-ratio/matrix corrections protocol are provided, along with the significance of the raw analytical total. Sections on accuracy of the standards-based k-ratio/matrix corrections protocol with EDS and processes of analysis when severe peak overlap occurs are also included. The article provides information on low-atomic-number elements, iterative qualitative-quantitative analysis for complex compositions, and significance of standardless analysis in the EDS software. It ends with a section on the processes involved in elemental mapping for major and minor constituents.

Identification of alloys using quantitative chemical analysis is an essential step during a metallurgical failure analysis process. There are several methods available for quantitative analysis of metal alloys, and the analyst should carefully approach selection of the method used. The choice of appropriate analytical techniques is determined by the specific chemical information required, the condition of the sample, and any limitations imposed by interested parties. This article discusses some of the commonly used quantitative chemical analysis techniques for metals. The discussion covers the operating principles, applications, advantages, and disadvantages of optical emission spectroscopy (OES), inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray spectroscopy, and ion chromatography (IC). In addition, information on combustion analysis and inert gas fusion analysis is provided.

This article discusses the capabilities and limitations of various material characterization methods that assist in the selection of a proper analytical tool for analyzing particulate materials. Commonly used methods are microanalysis, surface analysis, and bulk analysis. The techniques used for performing microanalysis include scanning electron microscopy and electron probe X-ray microanalysis. The article describes surface analysis techniques, including Auger electron spectroscopy, X-ray photoelectron spectroscopy, and ion-scattering spectroscopy. Bulk analysis techniques, such as X-ray powder diffraction, inductively coupled plasma atomic emission spectroscopy, atomic absorption spectroscopy, and atomic fluorescence spectrometry, are also discussed.

This article describes some of the common elemental composition analysis methods and explains the concept of referee and economy test methods in failure analysis. It discusses different types of microchemical analyses, including backscattered electron imaging, energy-dispersive spectrometry, and wavelength-dispersive spectrometry. The article concludes with information on specimen handling.

This article briefly discusses popular techniques for metals characterization. It begins with a description of the most common techniques for determining chemical composition of metals, namely X-ray fluorescence, optical emission spectroscopy, inductively coupled plasma optical emission spectroscopy, high-temperature combustion, and inert gas fusion. This is followed by a section on techniques for determining the atomic structure of crystals, namely X-ray diffraction, neutron diffraction, and electron diffraction. Types of electron microscopies most commonly used for microstructural analysis of metals, such as scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy, are then reviewed. The article contains tables listing analytical methods used for characterization of metals and alloys and surface analysis techniques. It ends by discussing the objective of metallography.

The overall chemical composition of metals and alloys is most commonly determined by X-ray fluorescence (XRF) and optical emission spectroscopy (OES), and combustion and inert gas fusion analysis. This article provides information on the capabilities, uses, detection threshold and precision methods, and sample requirements. The amount of material that needs to be sampled, operating principles, and limitations of the stated methods are also discussed.

The characterization, testing, and nondestructive evaluation of ceramics and glasses are vital to manufacturing control, property improvement, failure prevention, and quality assurance. This article provides a broad overview of characterization methods and their relationship to property control, both in the production and use of ceramics and glasses. Important aspects covered include the means for characterizing ceramics and glasses, the corresponding rationale behind them, and relationship of chemistry, phases, and microconstituents to engineering properties. The article also describes the effects that the structure of raw ceramic materials and green products and processing parameters have on the ultimate structure and properties of the processed piece. The effects that trace chemistry and processing parameters have on glass properties are discussed. The article describes mechanical tests and failure analysis techniques used for ceramics.

This article introduces various analytical techniques commonly used in the characterization of organic solids and liquids and discusses the challenges in performing the analysis, with examples. Some general advice in approaching a material analysis is also provided.

This article is a detailed account of optical emission spectroscopy (OES) for elemental analysis. It begins with a discussion on the historical background of OES and development trends in OES methods. This is followed by a description of the general principles and optical systems of OES, along with various types of emission sources commonly used for OES. Some of the processes involved in calibration and quantification of OES for direct solids analysis by the ratio method are then described. The article ends with a discussion on the applications of each type of emission sources.

In secondary ion mass spectroscopy (SIMS), an energetic beam of focused ions is directed at the sample surface in a high or ultrahigh vacuum (UHV) environment. The transfer of momentum from the impinging primary ions to the sample surface causes sputtering of surface atoms and molecules. This article focuses on the principles and applications of high sputter rate dynamic SIMS for depth profiling and bulk impurity analysis. It provides information on broad-beam instruments, ion microprobes, and ion microscopes, detailing their system components with illustrations. The article graphically illustrates the SIMS spectra and depth profiles of various materials. The quantitative analysis of ion-implantation profiles, instrumental features required for secondary ion imaging, the analysis of nonmetallic samples, detection sensitivity, and the applications of SIMS are also discussed.

This article is an overview of the division Surface Analysis of this volume. The division covers various developed surface-analysis techniques, such as scanning probe and atomic force microscopy. The division focuses on the analysis of surface layers that are less than 100 nm. A quick reference summary of surface-analysis methods is presented in this article.