bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical Microscopy
Authors: Nadeau Jay L. , Davidson Michael W.
Published: October 2012

The microstructure of a material is related directly to its physical, chemical, and mechanical properties as they are influenced by processing and/or the environment. Among the numerous investigative techniques used to study materials, optical microscopy, with its several diverse variations, is important to the researcher and/or materials engineer for obtaining information concerning the structural state of a material. Information gained using optical microscopy is complementary to other techniques and provides unique information to assess the microstructure of the sample. Though predominantly qualitative, in some cases quantitative measurements are made: some examples are for quantification of grain growth, the coarsening of precipitates during a process, or the evolution of structural domains or defects.

The goal of this article is to discuss the basic principles and structure of an optical microscope, including the light path, objective lenses, and illumination sources. In this new revised version of the article, fluorescence microscopy and its associated instrumentation are introduced. Practical tips for choosing a microscope, objectives, and accessories and for good microscopy practices are then given. A new Protocols section provides step‐by‐step guides to adjusting illumination and to some fluorescence applications.
Reflected‐Light Optical Microscopy
Authors: Nadeau, Jay L. , Davidson Michael W. , Connell Richard G.
Published: October 2012

Imaging of opaque specimens is performed using reflected rather than transmitted light. Illumination is supplied from above using orientations ranging from on‐axis (brightfield imaging) to highly oblique (oblique‐light microscopy; darkfield). The illuminating light might also be polarized (polarized light microscopy; differential interference contrast) or phase‐advanced or ‐retarded (phase contrast microscopy). Each of these techniques leads to generation of contrast from different features of a specimen, and several techniques can be used to complement each other and provide information about specimen composition, feature size, height, and other properties. Reflected‐light illumination is also the most common and most sensitive way to perform fluorescence microscopy on both transparent and opaque specimens. This article covers the principles behind the major techniques of reflected‐light optical microscopy and gives examples of materials applications, both traditional and emerging. The set‐up of the instrumentation required for each technique is given in detail, and Section “Practical Aspects of the Method” discusses the precise instrumentation and accessories needed to implement each technique. We also provide a guide to the most common imaging artifacts and pitfalls in reflected‐light microscopy.
Resonance Methods, Introduction
Authors: Hornak Joseph P.
Published: October 2012

Welcome to the chapter on resonance methods in the Characterization of Materials. There are several taxonomies which can be used to classify analytical techniques used to characterize materials. They may be grouped according to the probing electromagnetic energy (gamma‐ray, ultraviolet, visible, infrared, microwave, or radio frequency photons), energy level (nuclear, electronic, spin, vibrational, etc), the interaction (absorption, scattering, emission, etc) or the detection scheme (photoelectric, resonance, heat, etc), to name a few. In this chapter a simple taxonomy was adopted, the word resonance in the technique name.

By this taxonomy, resonance methods in materials science cover a broad range of techniques. These methods include nuclear magnetic resonance (NMR), nuclear quadrupole resonance (NQR), solid‐state (SS) NMR, electron paramagnetic resonance (EPR), ferromagnetic resonance (FMR), Mössbauer, and cyclotron resonance (CR) spectroscopies; andmagnetic resonance imaging (MRI). This chapter showshowthese extremely useful andunique techniques can help solve problems in materials science. The concept of a probe, located centrally within a material, is common to all these resonance techniques.
X
‐Ray Techniques, Introduction
Authors: Goldman Alan I.
Published: October 2012

X‐ray scattering and spectroscopy methods can provide a wealth of information concerning the physical and electronic structure of crystalline and noncrystalline materials in a variety of external conditions and environments. X‐ray powder diffraction, for example, is generally the first, and perhaps the most widely used, probe of crystal structure. Over the last 100 years, especially with the introduction of x‐ray synchrotron sources during the last 35 years, x‐ray techniques have expanded well beyond their initial role in structure determination.

This chapter explores the wide variety of applications of x‐ray scattering and spectroscopy techniques to the study of materials.
X‐ray and Neutron Diffuse Scattering Measurements
Authors: Ice Gene E. , Robertson James L. , Sparks Cullie J.
Published: October 2012

Diffuse scattering from crystalline solid solutions is used to measure local compositional order among the atoms, dynamic displacements (phonons), and mean species‐dependent static displacements. It can also provide information on defects including vacancies, interstitials, dislocations and truncated sample dimensions. In locally ordered alloys, fluctuations of composition and interatomic distances break the long‐range symmetry of the crystal within local regions and contribute to the total energy of the alloy. Local ordering can be a precursor to a lower temperature equilibrium structure that may be unattainable because of slow atomic diffusion. In addition to local atomic correlations, neutron diffuse scattering methods can be used to study the local short‐range correlations of the magnetic moments. Interstitial defects, as opposed to the substitutional disorder defects described above, also disrupt the long‐range periodicity of a crystalline material and give rise to diffusely scattered x‐rays, neutrons, and electrons.

This article will concentrate on the use of diffuse x‐ray and neutron scattering from single crystals to measure local chemical correlations and chemically specific static displacements. Particular emphasis is placed on the use of resonant (anomalous) x‐ray techniques to extract information on atomic size from binary solid solutions with short‐range order. By separating this diffuse intensity into its component parts we are able to recover pair correlation probabilities for the three kinds of pairs in a binary alloy. The interpretation of diffuse scattering associated with dynamic displacements of atoms from their average crystal sites are discussed briefly in this article.
X‐ray Magnetic Circular Dichroism
Authors: Lang Jonathan C.
Published: October 2012

This article presents the fundamentals of x‐ray magnetic circular dichroism (XMCD) measurements. The types of information obtained from XMCD are discussed, including several examples of recent experimental work. The instrumentation required for these measurements, methods for sample preparation, data analysis, and common experimental problems is presented.
Surface
X
‐Ray Diffraction
Authors: Felici Roberto
Published: October 2012

Surface x‐ray diffraction is a technique sensitive to the atomic structure and morphology of surfaces and interfaces. As x‐ray diffraction is used for the determination of three‐dimensional crystal structures and, in doing this, also crystallographic parameters such as Debye–Waller factors (thermal vibration amplitudes) or occupancy factors are also accessed, so surface x‐ray diffraction should be considered as a valid method for measuring these quantities too. Surface x‐ray diffraction also probes surface morphological properties, such as roughness and facet formation, and allows for the investigation of their thermodynamic and kinetic aspects, such as the study of phase transitions in surfaces, or of growth phenomena, or of catalytic reactions.
“Total” Ion Beam Analysis—3DImaging of Complex Samples UsingMeVIon Beams
Authors: Jeynes Chris
Published: October 2012

“Total‐IBA” indicates ion beam analysis (IBA) methods that use multiple individual IBA techniques (RBS, EBS, ERD, NRA, PIXE) self‐consistently. The synergy between the complementary techniques allows much more information about the sample to be extracted than is available from the sum of the information from each technique alone. Large new classes of samples are now tractable to ion beam analysis. 3D chemical imaging may even be possible by IBA.

In this chapter, the synergy between a number of closely related techniques for thin‐film depth profiling is described; they all use ion beams from megavolt (MV) accelerators as probes. This introductory article will not describe the techniques themselves but will concentrate specifically on the synergisms available.
Radiation Effects Microscopy
Authors: Lohstroh Annika
Published: October 2012

Radiation effect microscopy (REM) describes two related areas of research that are used to study semiconductor materials, devices and the effect of ionizing radiation on their electronic properties and performance. First, ion beam induced currents (IBIC) are studied in an imaging mode and/or second the effect of the ion impact on the logic state of microelectronic components is investigated as a function of position of the incident ion (single event effect (SEE) imaging).

This article reviews the most important developments and achievements of the technique during the last decade in terms of hardware and analysis. Several laboratories have developed dedicated data acquisition systems that allow the time resolved current or integrated current pulses to be digitized and the acquired waveforms to be analyzed offline. The time resolved data has improved the type of information that can be gained to include charge carrier drift velocities, diffusion effects and subsequently carrier lifetimes on nanosecond timescales. Computer modeling and simulations have been demonstrated to be very successful in describing the experimental data and will be increasingly applied to more complex device structures. Some laboratories have implemented temperature control to study temperature activated charge carrier re‐emission of defect levels and reduced temperatures can also be used to improve signal to noise. Currently, most common are wide band gap materials and semiconductor diodes or related devices as well as Silicon and SiGe based microelectronic chips, but there are indications that the application of REM might broaden in the future.
Nuclear Reaction Analysis (NRA) and Particle‐Induced Gamma‐Ray Emission (PIGE)
Authors: Kokkoris Michael
Published: October 2012

Recent developments in the field of ion beam analysis (IBA) have rendered nuclear reaction analysis (NRA) and particle‐induced gamma‐ray emission (PIGE) as two of the most promising techniques for the quantitative analysis and concentration depth profiling of light isotopes in complex matrices. This article summarizes the basic principles of both techniques, their strong points and weaknesses, as well as, the practical aspects for their implementation, including equipment and software packages. Moreover, special emphasis is put on the crucial issue of differential cross‐section libraries and evaluations.
Thermal Diffusivity by The Laser Flash Technique
Authors: Corbin Stephen F. , Turriff Dennis M.
Published: October 2012

Thermal diffusivity is an important material thermophysical property. The most widely used method for measuring thermal diffusivity is the laser flash technique. In this technique, a sample is placed within a controlled atmosphere furnace and subjected to a finite impulse of radiant energy on its front surface, through the use of a laser. The transport of heat through the sample, as a result of the laser impulse, causes a transient temperature rise on the rear surface of the specimen. This temperature rise is measured by an IR detector placed above the rear sample surface. The net result is a “thermogram” which is a plot of the rear‐face temperature versus time. Assuming a proper set‐up and careful experimentation, the transfer of heat under these conditions approximates one‐dimensional heat flow. Comparing the experimental data with one‐dimensional heat flow theoretical predictions, allows an estimation of thermal diffusivity.

There are several methods available to determine thermal diffusivity based on experimental and theoretical comparisons. The simplest method is to determine the “half‐rise time,”
t
0.5,
which is the time at which the experimentally measured rear‐face temperature reaches half of its maximum value. More accurate methods use sophisticated analysis algorithms to model and fit the entire experimental thermogram curve to an ideal theoretical curve by means of a nonlinear least‐squares procedure. These approaches can include corrections that account for the fact that the experimental measurements only approximate one‐dimensional heat flow conditions.

Using the thermogram curve fitting techniques, the measurement of thermal diffusivity of a range of material types including solid thermal insulators and conductors is possible. It is also possible to measure the apparent diffusivity of inhomogeneous samples such as composites and porous materials. Using two‐ and three‐layer analysis methods allows the measurement of thermal diffusivity of liquids. The layer methods can be extended to a determination of the thermal contact resistance of interfaces encountered in coated or bonded materials.
Single‐Crystal Neutron Diffraction
Authors: Koetzle Thomas F. , McIntyre Garry J.
Published: October 2012

Single‐crystal neutron diffraction allows determination of the distribution of nuclear scattering density in crystalline structures. It is especially suited to the location of hydrogen and characterization of hydrogen bonding in structures ranging from ice to small proteins, to the determination of magnetic structures, and to experiments on crystals under extreme conditions of temperature, magnetic field, and pressure. The principal requirement is a good quality single crystal of volume 0.1–10 mm3, although ongoing instrumental developments, including the introduction of large area detectors and Laue methods, are continually decreasing the lower limit. There are currently over 30 dedicated single‐crystal neutron diffractometers at steady‐state reactor and neutron spallation sources worldwide, accessible via peer‐reviewed proposal mechanisms. The experimental and analysis techniques are well established and are very similar to those used for single‐crystal x‐ray diffraction.
Fourier Transform Infrared (FTIR) Spectroscopy
Authors: Gaffney Jeffrey S. , Marley Nancy A. , Jones Darin E.
Published: October 2012

Infrared (IR) spectroscopy has always been a powerful tool for the identification of organic materials. However, with the development of Fourier transform infrared (FTIR) spectroscopy, it has become a more popular method for the quantitative analysis of complex mixtures, as well as the investigation of surface and interfacial phenomena. This chapter reviews the basic theory behind FTIR spectroscopy and describes the currently used instrumentation and its application to gas, liquid, bulk and powdered solid samples, and thin films using both transmission and reflectance methods, including specular, diffuse, and attenuated total reflectance (ATR) techniques. The optimization of instrumental parameters, sample handling techniques, signal processing, and data analysis are described. The characteristic vibrational absorption bands used for the identification of key chemical structures as well as methods for quantitative measurement of chemical composition are overviewed. Potential problems often encountered in using the different FTIR techniques in material and chemical species characterization and are also discussed in an effort to help the nonexpert in the field to make the best use of these powerful methods.
NMRSpectroscopy in the Solid State
Authors: Utz Marcel
Published: October 2012

Nuclear magnetic resonance spectroscopy of solid materials has seen substantial advances in the past two decades and has now become a powerful tool for the materials scientist. Its main strengths lie in the possibility of obtaining and dynamic information with molecular specificity in highly disordered and even fully amorphous materials. In this article, the fundamental interactions that affect the dynamics of nuclear spins are introduced. These include the chemical shift, dipolar spin–spin coupling, and quadrupolar coupling. In contrast to the liquid state, where molecules tumble rapidly compared to the timescale of NMR, all these interactions are aniostropic in the solid state, their magnitude depends on the orientation of the molecule with respect to the magnetic field. This anisotropy provides a wealth of structural and dynamic information, as discussed in the text.

Solid‐state NMR provides numerous opportunities to influence spin evolution and therefore render spectra selectively sensitive to structural and/or dynamic information of a desired type. Several such schemes, including magic angle spinning (MAS), cross‐polarization, multiple‐pulse, and Lee–Goldburg decoupling, as well as multiple‐quantum techniques, are discussed. Finally, specific applications of NMR techniques to the study of organic and inorganic solids, including techniques such as rotor‐synchronized magic angle spinning and DECODER (for the study of orientational order), spin–lattice relaxation time measurements and two‐dimensional exchange spectroscopy (molecular dynamics on various timescales) and multiple‐quantum magic angle spinning (chemical information from transition‐metal nuclei) are introduced.
Small‐Angle Neutron Scattering
Authors: Urban Volker S.
Published: October 2012

Small‐angle neutron scattering (SANS) probes structural details at the nanometer scale in a nondestructive way. This chapter gives an introduction to scientists who have no prior small‐angle scattering knowledge but seek a technique that allows elucidating structural information in challenging situations that thwart approaches by other methods. SANS is applicable to a wide variety of materials including metals and alloys, ceramics, concrete, glasses, polymers, composites, and biological materials. Isotope and magnetic interactions provide unique methods for labeling and contrast variation to highlight specific structural features of interest.In situstudies of a material's responses to temperature, pressure, shear, magnetic and electric fields, etc., are feasible as a result of the high penetrating power of neutrons. SANS provides statistical information on significant structural features averaged over the probed sample volume, and one can use SANS to quantify with high precision the structural details that are observed, for example, in electron microscopy. Neutron scattering is nondestructive; there is no need to cut specimens into thin sections, and neutrons penetrate deeply, providing information on the bulk material, free from surface effects. The basic principles of a SANS experiment are fairly simple, but the measurement, analysis, and interpretation of small‐angle scattering data involve theoretical concepts that are unique to the technique and that are not widely known. This chapter includes a concise description of the basics, as well as practical know‐how that is essential for a successful SANS experiment.
Multiscale Computational Characterization
Authors: Stan Marius
Published: October 2012

To understand, predict, and control matter and energy at the electronic, atomic, molecular, microstructural, and continuum levels, scientists need to investigate materials at a combination of length and time scales that are characteristic to relevant physical and chemical phenomena. As a consequence, experimental, theoretical, and computational methods must cover a wide range of space and time scales, starting with the nucleus and the electronic structure of individual or clustered atoms (Å), to nano/microstructural features, all the way to continuum properties of the sample (cm). Along the time scale, the investigation domain ranges from excitations (ps) to nucleation of new phases (ns), all the way to diffusion (minutes, hours) and aging characteristic times (months, years).

The article briefly reviews the major theoretical and computational methods used in multiscale characterization of materials, including atomistic (DFT, MD, AIMD, kMC), mesoscale (PF, DD, DDD), and continuum (FEM, FDM, FVM, CALPHAD) methods. Method coupling schemes are also discussed, from sequential to loose and tight concurrent coupling and ending with hybrid coupling methods. The multiscale characterization methodology is illustrated with results of simulations phenomena in Li‐ion and UO2materials. The chapter ends with a discussion of challenges and opportunities in the multiscale characterization of materials.
Handling Time and Temperature in Materials Simulations
Authors: Todorova Mira
Published: October 2012

Presented is an approach based on the seamless transmission of information obtained from modern electronic structure methods like density‐functional theory to thermodynamic functions. It allows to circumvent short term dynamics in a system, instead focusing on the long‐term impact an environment can have on it. It allows the identification of stable and metastable phases at relevant (
T,p
)‐conditions.

After outlining the basic principles of the methodology, examples of surfaces in contact with realistic environments are used to emphasise or illustrate different aspects of the method.

Particular attention is paid to possible approximations and their justification is discussed. The use of a direct screening approach, in which relevant structures are directly compared, as a possibility to deal with the configurational diversity of a system is discussed. Its advantages and disadvantages are discussed, and alternative routes are suggested. The importance of surface vibrational entropy is discussed in some depth, since it can have a large impact on formation Gibbs free energies and thus on the competition between relevant structures to gain thermodynamic stability at a given temperature.

The assumption underlying the thermodynamic approach are reviewed and routes to extend the thermodynamic formalism to account for kinetically stabilised surface reconstructions are presented. Experimental situations, which may give rise to chemical potentials beyond the thermodynamic limit are mentioned. Examples of equilibrium, extended and meta‐stable surface phase diagrams are shown and discussed.
High‐Temperature Drop Calorimetry
Authors: Meschel S. V. , Nash Philip
Published: October 2012

High‐temperature drop calorimetry is an experimental technique to measure enthalpy changes associated with reactions or change of temperature. The technique is widely used for the determination of enthalpies of formation of compounds. A variety of methods have been developed to characterize compounds formed by solid state, liquid, and gas reactions. The technique is also used to determine the specific heat of substances.
Potentiostatic and Galvanostatic Intermittent Titration Techniques
Authors: Levi Mikhael D. , Aurbach Doron
Published: October 2012

This article is concentrated on the essentials of potential and current pulses techniques, commonly known as potentiostatic and galvanostatic intermittent titration techniques (PITT and GITT, respectively). They were introduced around 35 years ago to provide thermodynamic and kinetic characterization of two‐ and three‐component metallic alloys with Li, and were thereafter widely used for studies of Li‐ion insertion into a variety of intercalation‐type anodes andcathodes. Emphasis is given to description of ion diffusion in finite (confined) space versus semi‐infinite diffusion in classical electrochemical cells. Special attention is also paid to intrinsic link between the diffusion time constant obtained from different electroanalytical techniques used and its dependence on the shape of the related ion intercalation isotherm. We also discuss the advantages and disadvantages in using separate incremental titration techniques as well as electrochemical impedance spectroscopy for detecting diffusion coefficients.
Microelectrodes
Authors: Molina Angela , Gonzalez Joaquin
Published: October 2012

Microelectrodes are electrodes with at least a characteristic dimension () in the micrometer range. The very small currents observed and their small size confers them exceptional advantages in the electroanalytical field: fast establishment of stationary responses, the great ratio of faradaic to charging currents, and decrease of the ohmic drop. They permit us to work with very small reaction volumes and at short timescales, and make possible to measure rate constants under a wide range of experimental conditions. Nanoelectrodes are electrodes with their characteristic dimension of a few tens of nanometers. They present particular size‐related electrochemical phenomena that have not yet been completely explored.

The main objective of this article is to show more fundamental and practical aspects derived from the use of microelectrodes and to discuss the applications of simple analytical and easily programmable equations for the electrochemical responses of interesting reaction schemes appearing in the characterization of electroacive species and materials.
Applications of Ferromagnetic Resonance
Authors: Lindner J. , Meckenstock R. , Farle M.
Published: October 2012

We show that ferromagnetic resonance described for the first time in the middle of the twentieth century has found nowadays numerous applications in nanoscale magnetic systems. The article discusses how ferromagnetic resonance can be used to quantitatively extract magnetic key parameters such as magnetic anisotropy energy, interlayer exchange coupling, and theg‐factor that provides access to orbital magnetism of single and coupled thin films as well as ensembles of magnetic nanoparticles. A short introduction to the theory and experimental approaches of ferromagnetic resonance is given in addition to the presentation of specific examples in detail.
In situX‐ray Measurement Methods
Authors: Stock Stuart R.
Published: October 2012

This article reviews in situ x‐ray measurement methods including x‐ray fluorescence (XRF), x‐ray scattering and x‐ray imaging. Three classes of in situ methods are covered: spectroscopy‐based, scattering‐based and imaging approaches. The spectroscopy treatment centers on x‐ray excited analysis of x‐ray fluorescence. The types of in situ characterization relying on x‐ray scattering include: identification and quantification of crystallographic phases present, crystallographic texture (i.e., pole figures; orientation distribution functions, odf), residual stress measurement and crystal defect characterization (x‐ray diffraction topography; rocking curve analysis). X‐ray imaging includes radiography and computed tomography as well as mapping using diffracted or fluorescent signal.
Spin‐Polarized Low‐Energy Electron Microscopy (SPLEEM)
Authors: N'diaye Alpha T. , Quesada Adrian
Published: October 2012

Electron microscopy techniques generally rely on controlling and measuring momentum and energy of electrons scattered at a sample. Spin‐polarized low energy electron microscopy (SPLEEM) introduces an additional physical dimension by allowing control of the spin‐polarization of the electron beam. The experimental setup is largely identical to low energy electron microscopy (LEEM), the key difference being that a spin‐polarized electron source is used in SPLEEM instead of an unpolarized electron source. In addition to the image contrast mechanisms that are available in LEEM, spin‐spin coupling of illumination electrons with electrons in the sample generates new contrast mechanisms that permit imaging of magnetic properties and phenomena. The electron energies that are most useful for SPLEEM imaging are often in the range of 0 to 30eV and SPLEEM is therefore as surface‐sensitive as LEEM.

In the following we will assume that the reader is familiar with the basic concepts of LEEM or refers to the Low‐ Energy Electron Microscopy article for reference. This article details the basic mechanism for spin resolved contrast and the design of the spin gun and spin manipulator. An overview of some of the capabilities of SPLEEM is given in the applications section where some recent experiments are reviewed.
In SituTEMMeasurement Methods
Authors: Gai Pratibha L. , Boyes Edward D.
Published: October 2012

Advances in atomic resolution‐environmental transmission electron microscopy (ETEM) for characterizing materials at the atomic scale, under controlled reaction conditions, are described. The ETEM allows the nanostructure of materials in their working state to be directly observed in real‐time. Examples of gas–solid and liquid–solid–gas reactions of technological interest are presented. Recent developments of double aberration‐corrected in‐situ environmental electron microscopy, under controlled reaction conditions at the sub‐Angstrom scale, are used to study bimetallic nanoparticles at high temperatures. Despite modifications to perform in‐situ studies, single‐atom imaging is possible. The results open up new opportunities for the characterization of dynamic materials.
Lorentz Microscopy
Authors: Petford‐Long A. K. , De Graef M.
Published: October 2012

In this article we review the principles of the method of Lorentz transmission electron microscopy (LTEM), including instrumental requirements, imaging modes (Fresnel, Foucault, low angle diffraction and differential phase contrast imaging), the use of a magnetizing holder, and the application of vector field tomography. The analysis of LTEM images usually requires an image simulation step, and we discuss the necessary theoretical background for such simulations. A magnetized sample modifies the phase of the electron wave, and this phase shift can be measured using the Transport‐of‐Intensity Equation formalism; we discuss how this approach works, and point out how one can define a resolution limit for magnetic observations. We conclude the article with comments on sample preparation as well as an outlook to future developments..
Elastic Recoil Detection Analysis
Authors: Schiettekatte François , Chicoine Martin
Published: October 2012

This chapter presents the elastic recoil detection (ERD) technique, an excellent complement to Rutherford backscattering spectrometry (RBS) and particle‐induced x‐ray emission (PIXE) for H detection on 0.5–2 MV accelerators. ERD with an absorber foil is easy to implement, featuring excellent sensitivity to light elements (H, He, Li) but with moderate depth resolution. This can be markedly improved by means of an electrostatic filter in place of the absorber. ERD using a heavy ion (HI) beam offers the possibility of acquiring a distinct spectrum for each element since the elements making the target are detected. HI‐ERD is therefore often more sensitive than RBS for which the signals of the different elements are superimposed on each other. The higher stopping power of HI gives access to improved depth resolution. If, historically, HI‐ERD required multi‐MV accelerators, recent implementations have been developed on 1.7 MV machines, the size used for RBS. However, more sophisticated detection systems are required to achieve such mass‐resolved, higher relative energy‐resolution detection. The larger uncertainty regarding the HI stopping power value also introduces higher uncertainty on the depth scale. Beam‐induced depth‐profile modification must always be monitored and can become significant with HI.
Scanning Helium Ion Microscopy
Authors: Guo H. X. , Fujita D.
Published: October 2012

Based on a field ion microscope, a scanning helium ion microscope has been developed for surface observation and modification. High‐brightness, small‐energy‐spread, and small‐wavelength helium ion beam is produced from a trimer of the gas field ion source. High‐resolution secondary electron images and Rutherford backscattered ion images are obtained by using an Everhart–Thornley detector and a microchannel plate detector, respectively. This novel microscope provides high resolution, high depth of focus observation and precise nanofabrication on various material surfaces.
Low‐Energy Ion Scattering
Authors: Brongersma Hidde H.
Published: October 2012

Low‐energy ion scattering (LEIS), also called ion scattering spectroscopy (ISS), is a tool for the analysis of the atomic composition of the surface as well as for a nondestructive in‐depth analysis of the near surface (0–10 nm). The analysis is based on backscattering of noble gas ions (He+, Ne+, Ar+, or Kr+) in the range of a few hundred to 10,000 eV. The extreme surface sensitivity of LEIS enables the selective analysis of the outermost atomic layer. This is precisely the layer that is largely responsible for many chemical and physical properties of materials. In combination with sputter depth profiling LEIS can also be used for the analysis of much deeper layers. Recent advances in the development of LEIS instruments now allow an essentially nondestructive (“static”) analysis, even of very sensitive materials like organic films. With the modern LEIS instruments one can analyze very rough amorphous insulating samples just as easily as conducting flat single crystals. The only restriction for samples being, that they can be put into vacuum for analysis. The applications of LEIS are, therefore, very wide and include important processes like adhesion, catalysis, diffusion, film growth, and electron emission. Alternative techniques include surface science tools, in particular X‐ray photoelectron spectroscopy (XPS), (TOF‐) SIMS, the high‐energy ion scattering techniques (HEIS), and medium‐energy ion scattering, MEIS.
Scanning Probe Microscopy Techniques, Introduction
Authors: Schwarz Alexander
Published: October 2012

With the Nobel Prize awarded to Binnig and Rohrer for the development of Scanning Tunneling Microscopy (STM) and the invention of Atomic Force Microscopy (AFM) by Binnig, Quate and Gerber, 1986 can be seen as the starting year of a new era in surface science. Microscopy, literally “looking at small things,” became possible down to the atomic level in real space and soon after many more so‐called Scanning Probe Microscopy (SPM) techniques based on either STM or AFM were born.
Magnetic Sensitive Scanning Tunneling Microscopy
Authors: von Bergmann Kirsten , Kubetzka André
Published: October 2012

The scanning tunneling microscope is capable of studying magnetism at surfaces down to the atomic scale. Using spin‐polarized tips even complex magnetic ground states of surfaces and nanostructures can be revealed. The technique of spinpolarized scanning tunneling microscopy can also be applied to study the switching of individual (super)paramagnetic objects as a function of temperature or magnetic field and recently it has been shown that the magnetic state of nanoscale objects can also be manipulated. In addition one can study magnetic excitations by employing spin excitation spectroscopy and thereby deduce the spin, the anisotropy, the type and strength of magnetic coupling and even relaxation times of single atoms or small clusters. Combining these techniques with atom manipulation provides access to fundamental magnetic phenomena on the atomic scale.
Atomic Force Microscopy and Spectroscopy
Authors: Hölscher Hendrik , Falter Jens , Schirmeisen André
Published: October 2012

Atomic force microscopy (AFM)—frequently also denoted as scanning force microscopy (SFM)—has developed into a workhorse for nano‐ and microtechnology. This technique is an offspring ofscanning tunneling microscopy(STM) and was also invented by Binnig et al[Binnig, G., Rohrer, H., Gerber, C., and Weibel, E. 1982. Surface studies by scanning tunneling microscopy.Phys. Rev. Lett.49(1):57–61; Binnig, G., Quate, C. F., and Gerber, C. 1986. Atomic force microscope.Phys. Rev. Lett.56(9):930]. Nowadays, it is used not only in physical, chemical, biological, and medical research laboratories, but also in many companies for everyday tasks like quality control. The success of the AFM is due to its high‐resolution imaging capabilities in combination with its versatility, making it possible to image surfaces down to the atomic scale. Due to its universality, AFM can be applied to a large variety of samples, and it can be adapted to many different environments (gaseous, liquid, or vacuum). The atomic force microscope can be operated in different modes, which can be categorized intostaticanddynamic‐modes. We give an introduction to the basic concepts of these two modes and present applications under different environmental conditions.
Magnetic Sensitive Scanning Probe Microscopy
Authors: Oral Ahmet
Published: October 2012

Magnetically sensitive scanning probe microscopes have been solving scientific and engineering problems over the last two decades. The magnetic dipole fields generated by a spherical magnetic particle with radius
a
decay with

. As the magnetic features of interest become smaller and smaller, the sensitivity of the apparatus has to be improved dramatically in order to measure and image the magnetic features within the specimen. An overview of these powerful methods is given in this article.
Scanning Thermal Microscopy
Authors: Ocola Leonidas E.
Published: October 2012

Scanning thermal microscopy (SThM) is a powerful characterization technique that has been steadily gaining recognition in the scientific community. It can be used on any solid material, and even in a liquid environment. This article covers a brief review of scanning probe history, SThM probes and an practical example on SThM microscopy. Care must be taken to interpret correctly any data acquired. This means to use alternate techniques to form a “big picture” of the tip – sample interaction. Simultaneous acquisition of topography and thermal data is not enough. Some key hurdles to overcome to make this characterization technique more accessible are the commercial availability of low‐loss probes and scanning thermal microscopes, and newer thermal probing techniques.
Low‐Energy Electron Microscopy
Authors: Flege J. I. , Tang W. X. , Altman M. S.
Published: October 2012

Low‐energy electron microscopy (LEEM) is a powerful method to study solid surfaces, thin films, and other surface‐supported nanostructures. Among the assorted electron‐based microscopies that are available, LEEM stands out for its strong surface sensitivity, real‐time imaging capability, and a number of unique contrast mechanisms that exploit the wave nature of imaging electrons. Furthermore, the capability to provide complementary reciprocal space information on a very small length scale using micro‐low energy electron diffraction in a LEEM brings many added strengths. LEEM is an ultrahigh vacuum technique, in which numerous approaches to in situ surface modification can be performed during imaging. These capabilities allow the study of structure, morphology and dynamic processes with excellent spatial and temporal resolution.
Dynamic Transmission Electron Microscopy
Authors: Evans James E. , Jungjohann Katherine L. , Browning Nigel D.
Published: October 2012

Dynamic transmission electron microscopy (DTEM) combines the benefits of high spatial resolution electron microscopy with the high temporal resolution of ultrafast lasers. The incorporation of these two components into a single instrument provides a perfect platform forin situobservations of material processes. However, previous applications for the first‐generation DTEM have focused primarily on observing structural changes occurring in samples exposed to high vacuum and have demonstrated a spatial resolution of 8 nm with a combined 15 ns temporal resolution. Yet, improved spatial resolution will be necessary for understanding dynamics of individual particles rather than bulk materials or thin films. Therefore, in order to expand the pump–probe experimental regime to more natural environmental conditions,in situgas and liquid chambers must be coupled with a second‐generation aberration‐corrected DTEM that has been modeled to achieve better than 0.3 nm spatial resolution with 1 μs temporal resolution. This chapter describes the current and future applications ofin situliquid DTEM to permit time‐resolved atomic scale observations in an aqueous environment. Although this chapter focuses mostly onin situliquid imaging, the same research potential exists forin situgas experiments and the successful integration of these techniques promises new insights for understanding nanoparticle, catalyst, and biological protein dynamics with unprecedented spatiotemporal resolution.
Pair Distribution Functions Analysis
Authors: Petkov Valeri
Published: October 2012

The foundations and practical aspects of atomic pair distribution functions analysis as a tool for characterizing the structure of materials of limited structural coherence are described in brief.
Resonant InelasticX‐ray Scattering
Authors: Leu Bogdan M. , Alp E. Ercan
Published: October 2012

Two resonant inelastic x‐ray scattering techniques are discussed: nuclear resonance inelastic x‐ray scattering (NRIXS) and resonant inelastic x‐ray scattering (RIXS). In NRIXS, the x‐ray energy is tuned around the nuclear excited level of the targeted Mössbauer nucleus to quantitatively probe the vibrational dynamics of the respective isotope, regardless of the atoms surrounding it. In RIXS, the incident energy coincides with an electronic absorption edge, probing intrinsic excitations in metals and other materials. We present the characteristics of these two techniques with their experimental requirements and include a few examples from the literature.
Sulfotransferases
Authors: Ma Bennett , Schrag Michael L.
Published: October 2012

The sulfotransferases (SULTs) are a family of phase II enzymes that catalyze the transfer of a sulfonate group (‐SO3−) from the cofactor 3′‐phosphoadenosine‐5′‐phosphosulfate (PAPS) to an acceptor molecule or substrate. Since these enzymes can conjugate with a wide variety of xenobiotics and endogenous substrates, they function not only as drug‐metabolizing enzymes but also modulators of physiological activities through conjugations of endogenous molecules such as steroids, catecholamines, and thyroid hormones. This chapter aims to provide drug metabolism scientists with an introductory overview on various aspects of SULTs along with challenges and complications associated with SULT‐mediated biotransformations, particularly encountered during the drug discovery and development process. In recent years, commercially available hepatocyte preparations and recombinant SULT enzymes facilitate the determination of SULT involvement for compounds of interest. However, significant challenges do remain. For example, when conducting reaction‐phenotyping experiments for SULT‐catalyzed conjugations, there is currently a lack of well‐characterized isoform‐specific probe substrates and inhibitors, in addition to a lack of well‐establishedin vitroincubation conditions. Kinetic experiments, too, often require careful interpretation, as profound substrate inhibition is rather common for sulfation reactions. From the toxicology stand‐point, sulfation may pose liability concerns due to the potential formation of reactive electron‐deficient metabolite species. It is recommended that investigators should take the time to explore and understand the properties of SULT‐mediated conjugations and their implications.
Anatomical and Physiological Parameters that Influence Gastrointestinal Absorption
Authors: DeSesso John M. , Jacobson Catherine F. , Williams Amy Lavin
Published: October 2012

The rate at which ingested compounds are absorbed into the bloodstream from the gastrointestinal (GI) tract and extent to which they are absorbed are governed by the physical‐chemical properties of the ingested compounds, the presence and identity of other substances in the GI tract, and the anatomical and physiological characteristics of the GI tract. This chapter describes the anatomical and physiological similarities and differences between humans and some common laboratory animals, with an emphasis on the absorptive surface area of the GI tract, the time it takes for materials to move through the GI tract, and the nature of the GI contents.
General Principles of Drug Distribution
Authors: Wallace Gillian C. , Ramsden Diane B. , Grant M. Helen
Published: October 2012

Pharmacokinetics is the study of the fate of a drug in the body over time. In order to understand this process it is important to gain insight into the absorption, distribution, biotransformation (metabolism), and excretion (ADME) properties of a drug. This chapter will focus on the importance of understanding the general principles of drug distribution. Distribution describes the reversible transfer of drug within body compartments. This typically occurs via the bloodstream after entry into systemic circulation. Distribution of the drug to organs, muscle or tissue can reduce its apparent plasma concentration, and the extent to which a drug is distributed can be determined by calculating the volume of distribution (Vd). There are many factors that can impact how a drug is distributed throughout the body. These include both physiochemical (pKa, lipophilicity, ionization and molecular size) and physiological (rate of blood flow, and binding to serum proteins) factors. Another important determinant of drug distribution is the involvement of transporters. Transporters have been shown to be expressed in many types of tissues including barrier membranes. An understanding of the interaction between drugs and transporters can provide key insights into drug distribution, pharmacological effects and potentially non‐linear pharmacokinetics. This chapter will provide a good understanding of the key determinants of drug distribution as well as how data is obtained, interpreted and utilized to build a model with the objective of developing a more comprehensive understanding of a new chemical entity.
Mechanisms of Drug Metabolism
Authors: Foti Robert S. , Rock Dan A. , Wienkers Larry C. , Wahlstrom Jan L.
Published: October 2012

The study of drug metabolism places significant importance on the molecular properties of the substrate and the topography of the enzyme's active site. Mechanisms of drug metabolism focus on the different reactions catalyzed within each family of drug‐metabolizing enzymes as well as the chemistry involved in phase I and II reactions. Concepts explored include enzyme‐catalyzed reaction mechanisms, physicochemical properties of substrate molecules that result in favorable sites of metabolism for a given enzyme, and factors that contribute to the regioselectivity and stereoselectivity observed for phase I and II drug‐metabolizing enzymes.