bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hall Effect and Conductivity Measurements in Semiconductor Crystals and Thin Films
Authors: Ellmer Klaus 
Published: October 2012

AbstractThe principle of the Hall effect and its application to the characterization of semiconductors are described. The physical origin of the Hall effect, discovered by Edwin H. Hall in 1879, is the Lorentz force acting on the charge carriers in a solid. The Hall voltage, which is generated perpendicular to the current flow in the sample, is proportional to the carrier mobility in the sample. Its sign depends on the type of the (majority) charge carrier (electrons or holes) and can be used to determine if a semiconductor is n‐ or p‐type. From the measured Hall voltage, the carrier concentrationnof the Hall sample can be determined. In combination with a conductivity (σ) measurement, the Hall mobility μHof the sample can be calculated according to μ = σ/(qn). Though in principle simple, the preparation of the Hall measurement samples and the interpretation of the measurements needs some care and the appropriate theory for the charge carrier transport in semiconductors. The normal Hall effect can be explained by a semiclassical theory, while the quantum Hall effect, discovered by von Klitzing in 1980, is a true quantum effect, which occurs only at very high fields at low temperatures in two‐dimensional electron gases. The so‐called von Klitzing constantRK = h/e2 = 25812.807557(18) Ω, which is extracted from a quantum Hall measurement, can be used for the definition of the international standard for resistance. Today, the (normal) Hall effect finds applications for the characterization of semiconductors and mainly for Hall sensors (produced in numbers of billions/year) for the measurement of magnetic fields, for noncontact (proximity) switches, speed detectors, position, and current sensors.
Electrochemical Techniques, Introduction
Authors: Bocarsly Andrew B. 
Published: October 2012

Abstract
Modern electrochemistry provides both a synthetic methodology to the materials scientist and an analytical tool for the evaluation of compositions and the kinetics of charge transfer processes. On the one hand, a variety of bulk materials and functional surfaces are prepared electrochemically. Historically this includes the electrorefining of materials such as aluminum, gold, and copper; surface preparation as illustrated in the anodization of aluminum, the electroetching of semiconductors, and the electroplating of thick metallic films. Similarly, the electrosynthesis of soft materials, for example, conducting organic polymers is an important route in select cases. More recently, the electrosynthesis of quantum structures either by direct deposition as in the case of ultra‐thin film layered metal structures, or by electroetching as exemplified in the synthesis of porous silicon has become an important application of electrochemistry. On the other hand, electroanalytical chemistry has been developed as an extremely sensitive physical characterization technique for the quantification of conducting and semiconducting surfaces and interfaces. The corrosion properties/processes of metallic surfaces and semiconductor electronic properties are two key areas where electrochemical characterization has had high impact. In keeping with the central analytical theme of this work, this chapter details the class of electrochemical techniques specifically aimed at characterizing materials and their interfaces.
Semiconductor Photoelectrochemistry
Authors: J. Anz Samir , M. Fajardo Arnel , J. Royea William , S. Lewis Nathan , J. Morris Amanda 
Published: October 2012

AbstractThis article discusses methods and experimental protocols in semiconductor electrochemistry. We first discuss the basic principles that govern the energetics and kinetics of charge flow at a semiconductor‐liquid contact. The principal electrochemical techniques of photocurrent and photovoltage measurements used to obtain important interfacial energetic and kinetic quantities of such contacts are then described in detail. After this basic description of concepts and methods in semiconductor electrochemistry, we describe methods for characterizing the optical, electrical, and chemical properties of semiconductors through use of the electrochemical properties of semiconductor‐liquid interfaces.
Optical Microscopy
Authors: Nadeau Jay L. , Davidson Michael W. 
Published: October 2012

AbstractThe 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

AbstractImaging 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

Abstract
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

Abstract
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

AbstractDiffuse 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.
Surface
X
‐Ray Diffraction
Authors: Felici Roberto 
Published: October 2012

Abstract
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

Abstract“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

AbstractRadiation 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

AbstractRecent 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

Abstract
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

AbstractSingle‐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

AbstractInfrared (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

AbstractNuclear 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

AbstractSmall‐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.