X-ray - Based Studies of Structural Dynamics in Solids and Liquids
Author
Summary, in English
To learn about changes in the structure of materials on the atom-level, time resolved x-ray scattering has proven a powerful technique. A wide variety of processes can be studied: from phase transitions in materials to vibrations in crystal lattices and pathways of chemical reactions. The aim of time-resolved studies is to follow these processes in real time.
The timescale for changes in structure varies considerably depending on the underlying mechanism. Processes involving neighboring atoms typically take about 100\,fs. Structure changes involving large groups of atoms or molecules occure on a timescale of picoseconds to nanoseconds. Different mechanisms can be used to trigger changes in structure. Laser pulses with a duration of less than 100\,fs can be produced routinely and are used to initiate ultrafast changes in the structure. Alternatively, short electrical pulses can be used to trigger structural changes in piezo-electric materials.
In this work, the main focus has been on experimental studies in order to deepen the understanding of structural changes in matter. The picosecond dynamics involved in the melting and recrystallization of a semiconductor, acoustic and thermal response of laser-excited solids, and the dynamics in the structure of a piezo-electric material have been studied. Additionally, instrumentation required for time-resolved x-ray scattering experiments has been developed.
Department/s
Publishing year
2011
Language
English
Publication/Series
Lund Reports in Atomic Physics
Volume
LRAP-429
Full text
Document type
Dissertation
Topic
- Atom and Molecular Physics and Optics
Status
Published
Supervisor
ISBN/ISSN/Other
- ISSN: 0281-2762
- ISBN: 978-91-7473-084-5
Defence date
25 March 2011
Defence time
10:15
Defence place
Lecture hall B, Department of Physics, Sölvegatan 14 A, Lund University Faculty of Engineering
Opponent
- Anton Plech (Dr)