Structures on Different Time Scales

Theo Woike, Dominik Schaniel

• Publisher: De Gruyter
• Year: 2018
• ISBN:
  9783110433906
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Physics
• Index: Physics

Volume 1 of this work presents theory and methods to study the structure of condensed matter on different time scales. The authors cover the structure analysis by X-ray diffraction methods from crystalline to amorphous materials, from static-relaxed averaged structures to short-lived electronically excited structures, including detailed descriptions of the time-resolved experimental methods. Complementary, an overview of the theoretical description of condensed matter by static and time-dependent density functional theory is given, starting from the fundamental quantities that can be obtained by these methods through to the recent challenges in the description of time dependent phenomena such as optical excitations.

Contents
Static structural analysis of condensed matter: from single-crystal to amorphous
DFT calculations of solids in the ground state
TDDFT, excitations, and spectroscopy
Time-resolved structural analysis: probing condensed matter in motion
Ultrafast science

Reinhard B. Neder

Static structural analysis of condensed matter: from single-crystal to amorphous

Keywords: X-ray scattering, structure analysis

Introduction

The main focus of this book is placed on the analysis of X-ray diffraction by dynamically changing structures. The details of the time-dependent formalism are presented in the chapter Time-resolved structural analysis of this book. Here the ground work for the time-resolved scattering is laid out, starting with the analysis of a static structure. Where relevant, differences between a static structure and the time-resolved structure are pointed out.

The time resolution limit in this chapter is down to the time-scale where the measurement still yields averaged positions, i.e., measurement/averaging time longer than typical vibration of atoms around equilibrium positions.

It is expected that the reader is familiar with a crystallographic description of crystals, which can be found in any textbook on crystallography, like Refs. [1–3]. Aspects of the structure determination from measured Bragg intensities can be found in textbooks [1, 4–8].

1Basic diffraction algorithm

An atomic structure can be studied in a diffraction experiment with any radiation whose wavelength is of the order of interatomic distances or shorter. This holds for X-rays, electrons, and neutrons. It is obvious that X-rays, which are a section of the electromagnetic spectrum in the wavelength range from approximately 0.2 down to 0.001 nm, can be diffracted by a grating with dimensions of the same order of magnitude. In a classical description, electrons and neutrons are treated as particles. Since their mass is very small, a quantum mechanical description of electrons and neutrons with wave properties is more appropriate for diffraction experiments. Given the wave nature of electrons and neutrons, they can be diffracted by crystals just as well as X-rays. The strength of the...

Table of contents

• Cover
• Title Page
• Copyright
• Dedication
• Contents
• List of Contributors
• Introduction
• Static structural analysis of condensed matter: from single-crystal to amorphous
• DFT calculations of solids in the ground state
• TDDFT, excitations, and spectroscopy
• Time-resolved structural analysis: probing condensed matter in motion
• Ultrafast science
• Index