Two-dimensional X-ray Diffraction

Bob B. He

• Publisher: Wiley
• Year: 2018
• ISBN:
  9781119356097
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Analytic Chemistry

An indispensable resource for researchers and students in materials science, chemistry, physics, and pharmaceuticals

Written by one of the pioneers of 2D X-Ray Diffraction, this updated and expanded edition of the definitive text in the field provides comprehensive coverage of the fundamentals of that analytical method, as well as state-of-the art experimental methods and applications. Geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis, and combinatorial screening are all covered in detail. Numerous experimental examples in materials research, manufacture, and pharmaceuticals are provided throughout.

Two-dimensional x-ray diffraction is the ideal, non-destructive analytical method for examining samples of all kinds including metals, polymers, ceramics, semiconductors, thin films, coatings, paints, biomaterials, composites, and more. Two-Dimensional X-Ray Diffraction, Second Edition is an up-to-date resource for understanding how the latest 2D detectors are integrated into diffractometers, how to get the best data using the 2D detector for diffraction, and how to interpret this data. All those desirous of setting up a 2D diffraction in their own laboratories will find the author's coverage of the physical principles, projection geometry, and mathematical derivations extremely helpful.

• Features new contents in all chapters with most figures in full color to reveal more details in illustrations and diffraction patterns
• Covers the recent advances in detector technology and 2D data collection strategies that have led to dramatic increases in the use of two-dimensional detectors for x-ray diffraction
• Provides in-depth coverage of new innovations in x-ray sources, optics, system configurations, applications and data evaluation algorithms
• Contains new methods and experimental examples in stress, texture, crystal size, crystal orientation and thin film analysis

Two-Dimensional X-Ray Diffraction, Second Edition is an important working resource for industrial and academic researchers and developers in materials science, chemistry, physics, pharmaceuticals, and all those who use x-ray diffraction as a characterization method. Users of all levels, instrument technicians and X-ray laboratory managers, as well as instrument developers, will want to have it on hand.

Chapter 1
Introduction

1.1 X‐Ray Technology, a Brief History

X‐ray technology has more than a hundred years of history and its discovery and development have revolutionized many areas of modern science and technology [1]. X‐rays were discovered by the German physicist Wilhelm Conrad Röntgen in 1895, who was honored with the Noble prize for physics in 1901. In many languages today X‐rays are still referred to as Röntgen rays or Röntgen radiation. This mysterious light was found to be invisible to human eyes, but capable of penetrating opaque object and expose photographic films. The density contrast of the object is revealed on the developed film as a radiograph. Since then X‐rays have been developed for medical imaging, such as for detection of bony structures and diseases in soft tissues like pneumonia and lung cancer. X‐rays have also been used to treat disease. Radiotherapy employs high energy X‐rays to generate a curative medical intervention to the cancer tissues. A recent technology, tomotherapy, combines the precision of a computerized tomography scan with the potency of radiation treatment to selectively destroy cancerous tumors while minimizing damage to surrounding tissue. Today, medical diagnoses and treatments are still the most common use of X‐ray technology.

The phenomenon of X‐ray diffraction by crystals was discovered in 1912 by Max von Laue. The diffraction condition in a simple mathematical form, which is now known as Bragg's law, was formulated by Lawrence Bragg in the same year. The Nobel Prize in Physics in consecutive two years (1914 and 1915) was awarded to von Laue and the elder and junior Braggs for the discovery and explanation of X‐ray diffraction. X‐ray diffraction techniques are based on elastic scattered X‐rays from matter. Due to the wave nature of X‐rays, the scattered X‐rays from a sample can interfere with each other, such that the intensity distribution is determined by the wavelength and the incident angle of the X‐rays and the atomic arrangement of the sample structure, particularly the long range order of crystalline structures. The expression of the space distribution of the scattered X‐rays is referred to as an X‐ray diffraction pattern. The atomic level structure of the material can then be determined by analyzing the diffraction pattern. Over its hundred year history of development, X‐ray diffraction techniques have evolved into many specialized areas. Each has its specialized instruments, samples of interest, theory, and practice. Single‐crystal X‐ray diffraction (SCD) is a technique used to solve the complete structure of crystalline materials, typically in the form of a single crystal. The technique started with simple inorganic solids and grew into complex macromolecules. Protein structures were first determined by X‐ray diffraction analysis by Max Perutz and Sir John Cowdery Kendrew in 1958, and both shared the 1962 Nobel Prize in Chemistry. Today, protein crystallography is the dominant application of SCD. X‐ray powder diffraction (XRPD), alternatively called powder X‐ray diffraction (PXRD), got its name from the technique of collecting X‐ray diffraction patterns from packed powder samples. Generally, X‐ray powder diffraction involves the characterization of the crystallographic structure, crystallite size, and orientation distribution in polycrystalline samples [2–5].

X‐ray diffraction (XRD), by definition, covers single crystal diffraction and powder diffraction as well as many X‐ray diffraction techniques. However, it has been accepted as convention that SCD is distinguished from XRD. By this practice, XRD is commonly used to represent various X‐ray diffraction applications other than SCD. These applications include phase‐identification, texture analysis, stress measurement, percentage crystallinity, particle (grain) size, and thin film analysis. An analogous method to X‐ray diffraction is the small angle X‐ray scattering (SAXS) technique. SAXS measures scattering intensity at scattering angles within a few degrees from the incident angle. SAXS pattern reveals the material structures, typically particle size and shape, in the nanometer to micrometer range. In contrast to SAXS, other X‐ray diffraction techniques are also referred to as wide angle X‐ray scattering (WAXS).

1.2 Geometry of Crystals

Solids can be divided into two categories: amorphou...

Table of contents

• Cover
• Table of Contents
• Preface
• Chapter 1: Introduction
• Chapter 2: Geometry and Fundamentals
• Chapter 3: X-Ray Source and Optics
• Chapter 4: X-Ray Detectors
• Chapter 5: Goniometer and Sample Stages
• Chapter 6: Data Treatment
• Chapter 7: Phase Identification
• Chapter 8: Texture Analysis
• Chapter 9: Stress Measurement
• Chapter 10: Small Angle X-ray Scattering
• Chapter 11: Combinatorial Screening
• Chapter 12: Miscellaneous Applications
• Chapter 13: Innovation and Future Development
• Appendix A: Values of Commonly Used Parameters
• Appendix B: Symbols
• Index
• End User License Agreement