Studying Atomic Dynamics with Coherent X-rays

by Michael Leitner

Overview

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.

Product Details

ISBN-13:	9783642436222
Publisher:	Springer Berlin Heidelberg
Publication date:	02/23/2014
Series:	Springer Theses
Edition description:	2012
Pages:	98
Product dimensions:	6.10(w) x 9.25(h) x 0.02(d)

Table of Contents

Introduction.- Theory.- Linking Theory to Experiments.- Characteristics of Diffusion in Selected Systems.- Data Evaluation.- Considerations Concerning the Experiment.- Experimental Results.- Outlook.- Appendix.