Diffusion in solids at moderate temperatures is a well-known phenomenon. However, direct experimental evidence about the responsible atomic-scale mechanisms has been scarce, due to difficulties in probing the relevant length- and time-scales. The present thesis deals with the application of X-ray Photon Correlation Spectroscopy (XPCS) for answering such questions. This is an established method for the study of slow dynamics on length-scales of a few nanometres. The scattered intensity in the diffuse regime, i.e. corresponding to atomic distances, is very low, however, and so it has so far been considered impossible to use XPCS for this problem. Threefold progress is reported in this work: It proposes a number of systems selected for high diffuse intensity, it optimizes the photon detection and data evaluation procedures, and it establishes theoretical models for interpretating the results. Together these advances allowed the first successful atomic-scale XPCS experiment, which elucidated the role of preferred configurations for atomic jumps in a copper-gold alloy. The growth in available coherent X-ray intensity together with next-generation X-ray sources will open up a wide field of application for this new method.

This thesis provides the first successful study of jump diffusion processes in glasses on the atomic scale, utilizing a novel coherent technique. This new method, called atomic-scale X-ray Photon Correlation Spectroscopy or aXPCS, has only recently been proven to be able to capture diffusion processes with atomic resolution in crystal systems. With this new toolkit for studying atomic diffusion in amorphous systems, new insight into basic processes in a wide range of technically relevant materials, like fast ionic conductors, can be obtained.

Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources driven by laser-plasma accelerators. The applications of the most advanced light sources and the advent of nanobeams and fully coherent x-rays allow experiments from which scientists in the past could not even dream. Examples are the diffraction with nanometer resolution, imaging with a full 3D reconstruction of the object from a diffraction pattern, measuring the disorder in liquids with high spatial and temporal resolution. The 20th century was dedicated to the development and improvement of synchrotron light sources with an ever ongoing increase of brilliance. With ultrahigh brilliance sources, the 21st century will be the century of x-ray lasers and their applications. Thus, we are already close to the dream of condensed matter and biophysics: imaging single (macro)molecules and measuring their dynamics on the femtosecond timescale to produce movies with atomic resolution.

A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms.

A collection of abstracts for the 20th American Conference on Crystal Growth and Epitaxy (ACCGE-20) and 17th U.S. Biennial Workshop on Organometallic Vapor Phase Epitaxy (OMVPE-17) and The Second 2D Electronic Materials Symposium.

Covering the latest research in alloy physics together with the underlying basic principles, this comprehensive book provides a sound understanding of the structural changes in metals and alloys -- ranging from plastic deformation, deformation dynamics and ordering kinetics right up to atom jump processes, first principle calculations and simulation techniques. Alongside fundamental topics, such as crystal defects, phase transformations and statistical thermodynamics, the team of international authors treats such hot areas as nano-size effects, interfaces, and spintronics, as well as technical applications of modern alloys, like data storage and recording, and the possibilities offered by materials design.

The invention of ultrafast optical lasers with pulse durations comparable to vibrational periods in solids and motions of molecules undergoing structural changes has provided a look at the dynamics that govern important processes in nature. X-rays, on the other hand, with wave-lengths comparable to the distances between atoms, have been the key tool for the study of the average structure of liquids and solids at atomic resolution. With recent developments in ultrafast x-ray sources, the combination of appropriate temporal resolution and spatial resolution is opening new scientific opportunities for direct observation of atomic-scale dynamics. The Sub-Picosecond Pulse Source at SLAC is just such a source. The science and technology of ultrafast x-ray studies will be discussed in this context, as will the extension of these studies to opportunities afforded by the Linear Coherent Light Source x-ray free-electron laser.