Preface
This book is based on presentations to the International Conference of X-Ray Microscopy and Spectromicroscopy, XRM 96, which took place in Würzburg, August 19–
23, 1996. The conference also celebrated the 100th anniversary of the discovery of Xrays by Wilhelm Conrad Röntgen on November 8, 1895, in Würzburg.
This book contains state-of-the-art reviews and up-to-date progress reports in the
field of X-ray microscopy and spectromicroscopy, including related new X-ray optics
and X-ray sources. It reflects the lively activities within a relatively new field of
science which combines the development of new instruments and methods with their
applications to numerous topical scientific questions. The applications range from
biological and medical topics, colloid physics, and soil sciences to solid-state physics,
material sciences, and surface sciences. Their variety demonstrates the interdisciplinary and cooperative character of this field and the growing demand for microscopic and spectromicroscopic information on the nanometer scale and under specific
sample conditions, for example in wet (natural) surroundings or on a solid surface.
We emphasize that the enormous progress in this field that has been made recently
and will be made in the future, concerning the resolution, contrast, and versatility,
results from the availability of high-brilliance soft X-ray radiation provided especially
by the third-generation X-ray synchrotron sources such as ALS in Berkeley,
ELETTRA in Trieste, or BESSY II in Berlin. Of similar interest is the further
development of improved X-ray optics and X-ray condensers with high numerical
apertures and high-resolution X-ray objectives, both with high efficiencies.
In a transmission X-ray microscope (TXM) the X-ray objective generates an
enlarged image of the specimen. In a scanning transmission X-ray microscope
(STXM) the X-ray objective forms a microprobe used to examine the specimen one
pixel at a time. Experiments performed with both types of instrument are presented in
this book, including the new developments of cryo-X-ray microscopy and X-ray
microscopic tomography. A variety of scientific applications have been addressed in
fields of biological and medical research (e.g., cells, sperm, algae, bone), in colloid
physics and soil sciences (e.g., interactions of soil colloids with surfactants and microorganisms, aggregation phenomena, lipid membranes), and in solid-state physics
(magnetic domains).
Spectromicroscopy and microspectroscopy have added a new, spectroscopic,
dimension to the microscopy of surfaces. The microscopic information can be
obtained either by imaging photoexcited electrons by scanning focused X-ray beam
across a sample surface, whereas the spectroscopic information is derived from the
variation of the photon energy and/or from the energy analysis of the emitted
electrons. Both approaches have several advantages and are realized in different
instruments, some of which are presented and discussed in this book. The availability
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Preface
of such instruments has, of course, lead to numerous applications, some of which are
described here. They cover a wide range from medical research to material sciences
and applications (e.g., polymers, thin-film solar cells, magnetic layers).
To keep the book to a reasonable size, only some of the contributions have been
printed. However, all contributions listed in the table of contents can be found on the
attached compact disk.
In our capacity as organizers we would like to thank the University of Würzburg
for its hospitality and assistance during the conference. We are grateful to the
Deutsche Forschungsgemeinschaft and the Balzers Hochvakuum AG as the main
sponsors.
We would like to thank all authors for their cooperation and all of our coworkers
who have contributed to the organization of the conference, especially Dr. Rainer
Fink, Dr. Kirsten Thieme, Lieselotte Reichert, and Britta Leinemann.
Göttingen and Würzburg,
Mai 1998
Jürgen Thieme
Günter Schmahl
Dietbert Rudolph
Eberhard Umbach