Lensless Holography Methods For Soft X Ray Resonant Coherent Imaging

The ability to interpret and inverse x-ray diffraction patterns from crystals has largely shaped our understanding of the structure of matter. However, structure determination of noncrystalline objects from their diffraction patterns is a much more difficult task. The dramatic increase in available coherent x-ray photon flux over the past decade has made possible a technique known as lensless coherent diffractive imaging (CDI), that addresses exactly this problem. The central question around CDI is the so-called phase problem: upon detection of the diffraction intensity, the phase information of the diffracted wave is inevitably lost. Generally, the phase problem is approached using iterative phase retrieval algorithms. Holographic methods, through interference with reference diffractions, encode the phase information directly inside the measured x-ray holograms, and are therefore able to avoid the stagnation and uniqueness problems commonly encountered by the iterative algorithms. This dissertation discusses two novel holographic methods for coherent lensless imaging using resonant soft x-rays. The first part focuses on generalizing the multiple-wavelength anomalous diffraction technique, a highly successful method for solving the crystal structures of biomacromolecules, into a multiple-wavelength holography technique for nanoscale resonant x-ray imaging. Using this method I show element specific reconstructions of nanoparticles and magnetization distribution in magnetic thin films with sub 50 nm resolution. The second part discusses progress in X-ray Fourier holography, an ultrafast lensless imaging platform that can be used with the upcoming x-ray free electron lasers. In particular, I will present experiments using two novel types of extended reference structures that bring the resolution beyond the precision of reference fabrication, previously regarded as the resolution limit for x-ray Fourier transform holography. Finally, future applications of holographic methods, especially experimental considerations for time-resolved studies of nanostructures using X-FELs, will be discussed.

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.

This book describes energy loss magnetic chiral dichroism (EMCD), a phenomenon in energy loss spectroscopy discovered in 2006. EMCD is the equivalent of XMCD but is based on fast probe electrons in the electron microscope. A spatial resolution of 2 nm has been demonstrated, and the lattice-resolved mapping of atomic spins appears feasible. EMCD is,

An up-to-date overview of the different x-ray based methods in the hot fields of nanoscience and nanotechnology, including methods for imaging nanomaterials, as well as for probing the electronic structure of nanostructured materials in order to investigate their different properties. Written by authors at one of the world's top facilities working with these methods, this monograph presents and discusses techniques and applications in the fields of x-ray scattering, spectroscopy and microscope imaging. The resulting systematic collection of these advanced tools will benefit graduate students, postdocs as well as professional researchers.

This text describes optics mainly in the 10 to 500 angstrom wavelength region. These wavelengths are 50 to 100 times shorter than those for visible light and 50 to 100 times longer than the wavelengths of medical x rays or x-ray diffraction from natural crystals. There have been substantial advances during the last 20 years, which one can see as an extension of optical technology to shorter wavelengths or as an extension of x-ray diffraction to longer wavelengths. Artificial diffracting structures like zone plates and multilayer mirrors are replacing the natural crystals of x-ray diffraction. Some of these structures can now be fabricated to have diffraction-limited resolution. The new possibilities are described in a simple, tutorial way.

Covering the key theories, tools, and techniques of this dynamic field, Handbook of Nanophysics: Principles and Methods elucidates the general theoretical principles and measurements of nanoscale systems. Each peer-reviewed chapter contains a broad-based introduction and enhances understanding of the state-of-the-art scientific content through fund