Amorphous Solids

1. Introduction.- 1.1 Historical Background.- 1.2 Tunneling States.- 1.2.1 Energy Levels.- 1.2.2 Transition Probabilities and Relaxation Times.- 1.3 Organization of the Book.- References.- 2. The Vibrational Density of States of Amorphous Semiconductors.- 2.1 The Vibrational Density of States.- 2.2 Experimental Techniques.- 2.3 The Theoretical Problem.- 2.4 Brute Force Theory.- 2.4.1 Turning the Handle.- 2.4.2 Some Results of Brute Force.- 2.5 More Refined Approaches.- 2.5.1 Analytical Ideas.- 2.5.2 The Bethe Lattice.- 2.5.3 Indirect Numerical Methods.- 2.6 The Incorporation of Matrix Elements.- 2.7 Can One Derive Structural Information from g(?)?.- 2.8 A Less Myopic View of the Field.- References.- 3. Low Temperature Specific Heat of Glasses.- 3.1 Review of the Experimental Situation.- 3.2 Comparison with Theoretical Models.- 3.2.1 The Tunneling Model.- 3.2.2 The Cellular Model.- 3.3 Summary and Outlook.- References.- 4. The Thermal Expansion of Glasses.- 4.1 Theoretical Background.- 4.2 The High Temperature Expansion of Vitreous Silica.- 4.3 The Low Temperature Expansion of Glasses.- 4.3.1 Experimental Results.- 4.3.2 Discussion.- References.- 5. Thermal Conductivity.- 5.1 Thermal Transport in Crystalline Materials.- 5.2 Thermal Transport in Amorphous Materials.- 5.2.1 The Phonon Mean Free Path.- 5.2.2 Phonon Scattering Mechanisms.- 5.2.3 Summary.- 5.3 Probing the Localized Excitations.- 5.4 Synopsis.- References.- 6. Acoustic and Dielectric Properties of Glasses at Low Temperatures.- 6.1 General Comments.- 6.2 Acoustic and Dielectric Properties Above 10 K.- 6.2.1 Absorption.- 6.2.2 Sound Velocity and Dielectric Constant.- 6.3 Acoustic and Dielectric Properties Below 10 K.- 6.3.1 Acoustic and Dielectric Absorption.- a) Relaxation Effects.- b) Resonant Interaction.- 6.3.2 Sound Velocity and Dielectric Constant.- 6.3.3 Acoustic Dielectric "Cross"-Experiments.- 6.4 Theoretical Description of the Acoustic and Dielectric Properties by Two-Level Systems.- 6.4.1 Dynamical Properties of Two-Level Systems.- 6.4.2 Absorption Due to a Distribution of Two-Level Systems.- 6.4.3 Variation of Sound Velocity and Dielectric Constant.- 6.5 Comparispn Between Theory and Experiment.- 6.6 Microscopic Description: Tunneling Model.- 6.7 Summary.- References.- 7. Relaxation Times of Tunneling Systems in Glasses.- 7.1 Background.- 7.2 Resonance Dynamics of Two-Level Systems.- 7.2.1 Tunneling Model.- 7.2.2 Longitudinal Relaxation Time T1.- a) One-Phonon Relaxation.- b) Conduction Electron Relaxation.- 7.2.3 Transverse Relaxation Time T'2.- 7.2.4 Spontaneous Echo Decay.- 7.2.5 Stimulated Echo Decay.- 7.3 Experiments Measuring Relaxation Times.- 7.3.1 Acoustic Saturation.- 7.3.2 Saturation Recovery.- 7.3.3 Linewidth.- 7.3.4 Two-Pulse Phonon Echo.- 7.3.5 Two-Pulse Electric Echo.- 7.3.6 Three-Pulse Phonon Echo.- 7.3.7 Three-Pulse Electric Echo.- 7.4 Critical Assessment of Data.- 7.4.1 T1 Results.- a) Three-Pulse Echoes.- b) Saturation Recovery.- c) Distribution of Decay Times.- 7.4.2 T'2 Results.- a) Two-Pulse Echoes.- b) Linewidth.- 7.5 Conclusions.- References.- 8. Low Frequency Raman Scattering in Glasses.- 8.1 Introductory Comments.- 8.2 Vibrational Raman Spectrum of First Order.- 8.2.1 Experimental Results.- 8.2.2 Theory of Low-Frequency Spectrum.- a) Continuum Theory.- b) Bond Polarizabil ity Model.- 8.3 Quasielastic Spectrum.- 8.3.1 Experimental Results.- 8.3.2 Theory.- a) Physical Origin of the Quasielastic Scattering.- b) Relation Between Raman Scattering and Ultrasonic Absorption.- c) Defect Model.- 8.4 Conclusion.- References.- Additional References with Titles.- Subject and Material Index.