Spectroscopy is a versatile tool for the characterization of materials, and photons in the visible frequency range of the electromagnetic spectrum have been used successfully for more than a century now. But other elementary particles such as neutrons, muons and x-ray photons have been proven to be useful probes as well and are routinely generated in modern cyclotrons and synchrotrons. They offer attractive alternative ways of probing condensed matter in order to better understand its properties and to correlate material behavior with its structure. In particular, the combination of these different spectroscopic probes yields rich information on the material samples, thereby allowing for a systematic investigation down to atomic resolutions. This book gives a practical account of how well they complement each other for 21st century material characterization, and provides the basis for a detailed understanding of the scattering processes and the knowledge of the relevant microscopic interactions necessary for the correct interpretation of the experimentally obtained spectroscopic data.
Walter E. Fischer (1939-2008) was the former head of the Department of Condensed Matter Research with Neutrons and Muons (NUM) at the Paul Scherrer Institute (PSI) in Villigen, Switzerland. He pioneered in establishing the spallation neutron source SINQ at PSI which went into operation in the mid-1990s. Later he foundes a condensed matter theory group to complement the experimental work at the neutron source.
PREFACE INTRODUCTION Some Historical Remarks The Experimental Methods The Solid as a Many Body Survey over the Spectral Region of a Solid THE PROBES, THEIR ORIGIN AND PROPERTIES Origin Properties Magnetic Field of the Probing Particles INTERACTION OF THE PROBES WITH THE CONSTITUENTS OF MATTER The Nuclear Interaction of Neutrons Interaction of X-Rays with Atomic Constituents Magnetic Interaction Corollar SCATTERING ON (BULK-)SAMPLES Introduction The Sample as a Thermodynamic System The Scattering Experiment Properties of the Scattering and Correlation Function General Form of Spin-Dependent Cross-Sections Summary and Conclusions GENERAL THEORETICAL FRAMEWORK Time Development of the Density Operator Generalized Suspectibility Dielectric Response Function and Sum Rules APPENDIX A: PRINCIPLES OF SCATTERING THEORY Potential Scattering (Supporting Section 3.1.1) Two Particle Scattering (Supporting Section 3.1.2) Abstract Scattering Theory (Supporting Section 3.2) Time-Dependent Perturbation Scattering of Light on Atoms Polarization and its Analysis APPENDIX B: FORM FACTORS APPENDIX C: REMINDER ON STATISTICAL MECHANICS The Statistical Operator P The Equation of Motion Entropy Thermal Equilibrium - The Canonical Distribution Thermodynamics APPENDIX D: THE MAGNETIC MATRIX-ELEMENTS The Trammell Expansion The Matrix Elements Conclusion APPENDIX E: THE PRINCIPLE OF A MSR-EXPERIMENT APPENDIX F: REFLECTION SYMMETRY AND TIME-REVERSAL INVARIANCE Invariance Under Space Inversion Q Invariance Under Time Reversal APPENDIX G: PHONON COUPLING TO HEAT BATH