Nexafs Spectroscopy

ISBN-13: 9783642081132 / Angielski / Miękka / 2010 / 404 str.

Joachim Stohr

Opis

The purpose of this book is the development of the principles and experimental techniques underlying near edge X-ray absorption fine structure (NEXAFS) spectroscopy and the demonstration of the power of the technique for the study of the electronic and crystallographic structure of low-Z molecules bonded to surfaces. Low-Z molecules are defined as those consisting of hydrogen, carbon, nitrogen, oxygen and/or fluorine atoms, which are particularly important in surface chemistry. This book is the first comprehensive treatment of the subject and presents a unified picture of theoretical and experimental concepts and results. It develops all concepts from an elementary level and is suitable for students and researchers without extensive prior knowledge in X-ray absorption spectroscopy. On the other hand, it discusses state-of-the-art instrumentation, analysis techniques, and experimental and theoretical results and is therefore also suited for the advanced spectroscopist. The spectra of free molecules are discussed first, since their understanding provides the basis for understanding spectra of molecules bonded to surfaces, the main topic of the book. The connection to spectra of polymeric molecules is also made. The book may therefore be of interest not only to surface scientists but also to researchers studying free molecules or polymers. The various molecular adsorption systems studied by NEXAFS are tabulated. Future scientific opportunities making use of the NEXAFS technique in conjunction with advanced synchrotron radiation sources are also discussed. These range from element-specific microscopy stud- ies of solid surfaces to studies of molecular conformations at liquid surfaces. Portola Valley, CA J.

Spis treści

1. Introduction.- 2. Theory of Inner Shell Excitation Spectra.- 3. Symmetry and Molecular Orbitals.- 4. Experimental and Calculated K-Shell Spectra of Simple Free Molecules.- 5. Principles, Techniques, and Instrumentation of NEXAFS.- 6. Spectra of Condensed, Chemisorbed, and Polymeric Molecules: An Overview.- 7. Analysis of K-Shell Excitation Spectra by Curve Fitting.- 8. ?* Resonance Position and Bond Length.- 9. The Angular Dependence of Resonance Intensities.- 10. Selected Applications of NEXAFS.- 11. A Look into the Future.- Appendices.- A. Derivation of the EXAFS Equation.- B. Chemisorbed Molecules Studied by NEXAFS.- References.

Blurb

This comprehensive treatment of the fundamental principles and applications of NEXAFS spectroscopy develops all concepts from an elementary level, presenting a unified picture of the latest theoretical and experimental results. The power of this technique is demonstrated, in particular, in the application to low-Z molecules bonded to surfaces, systems of special interest in surface chemistry, where NEXAFS reveals the electronic and structural properties of the molecules. While researchers and students without extensive prior knowledge of X-ray absorption spectroscopy are catered for by the systematic presentation of the underlying concepts, pracicing spectroscopists will find here details of state-of-the-art instrumentation in analysis techniques, and results, along with tabulated information about the various molecular adsorption systems that have already been studied by NEXAFS.