Phonon Scattering in Solids

The Second International Conference on Phonon Scattering in Solids was held at the University of Nottingham from August 27th - 30th 1975. It was attended by 192 delegates from 24 countries who were accompanied by 43 members of their families. Eleven invited papers were read and 96 contributed papers; the contributed papers were in two parallel sessions. The Conference included the topics of the two International Conferences held in France in 1972, in Paris and at Ste Maxime. The Conference brought together workers concerned with many aspects of phonon scattering in solids and liquid helium. Some of the work reported were studies of the intrinsic properties of diel­ ectric materials such as the effects of anharmonicity, dispersion and anisotropy on phonon propagation and the conditions for the existence of zero sound and second sound modes. Work was also pres­ ented on various aspects of phonon interaction with free electrons in metals and semiconductors. A substantial part of the Conference was devoted to phonon spectroscopy - investigations of the energy levels of ions or neutral impurities by observing the resonant absorp­ tion or scattering of phonons. The materials being studied include paramagnetic and parae1ectric solids, amorphous systems in which the 'impurities' appear to be intrinsic, and semiconductors. Work was reported on the use of phonons to observe phase transitions; in some cases the cooperative phase also arises through strong spin­ phonon coupling. One of the intriguing unsolved problems discussed in detail at the Conference is the Kapitza conductance problem.

Kapitza Conductance and Surfaces.- The Thermal Boundary Resistance (invited paper).- Reflection Coefficient of Phonons between 15 and 200 GHz at a Solid-Liquid Helium Interface.- A Model of Inelastic Heat-Transfer Mechanism for the Excess Kapitza Conductance.- A New Kapitza Investigation: Detecting Backscattered Phonons with Tunnel Junction and Bolometer Simultaneously.- The Angular Distribution of Phonons Radiated from the Cleaved 100 Faces of NaF, KCl, and MgO into Liquid 4He.- Energy Transfer between a Solid and Helium by Excited Atoms.- Path-Integral Formulation of the Theory of Thermal Boundary Resistance.- The Role of Electrons in the Kapitza Resistance of Lead.- Influence of Dislocations on the Kapitza Conductance of Clean Copper Surfaces.- Influence of Surface Contamination on the Kapitza Conductance of Copper, Silver, Molybdenum, and Beryllium.- A Direct Approach to Finite Phonon Transport (Realistic Transfer at Boundaries).- Reflection of Phonons in Liquid 4He from Solid Surfaces.- The Thermal Boundary Resistance at Epoxy-Resin/Metal Interfaces at Liquid Helium Temperatures.- Determination of Kapitza Conductance from the Velocity of Destruction of Superconductivity by Current.- Computer-Simulated Scattering of Envelope Soliton from Impurity and Interface in a One-Dimensional Nonlinear Lattice.- Surface Phonon Scattering by Density Fluctuation on Solid Surfaces.- Theory of Rayleigh Wave Scattering by Mass Defects and Surface Roughness.- Phonon Diffusion in a Temperature Gradient.- Phonon Diffusion and Temperature Field in Metals.- Role of Umklapp in Acoustic Boundary Resistance.- Discussion on Kapitza Conductance and Surfaces.- Second and Zero Sound.- Propagation in Liquid Helium (invited paper).- A First Step Towards Zero Sound in Ionic Crystals.- Low Temperature Thermal Conductivity of (NO3)2Ba, (NO3)2Sr, and (NO3)2Pb Single Crystals.- Ballistic Phonons and the Transition to Second Sound in Solid 3He.- On the Temperature Behavior of Second Sound and Poiseuille Flow in Solids.- The Propagation of High Frequency Thermal Waves in Dieletric Crystals.- Light Scattering from Second Sound in NaF.- Discussion on Second and Zero Sound.- Amorphous Systems.- Phonon Scattering in Amorphous Solids (invited paper).- Low-Energy Phonons in Amorphous Materials (invited paper).- Propagation of Ultrasonic Longitudinal and Transverse Sound Waves in Glasses at Very Low Temperatures.- Phonons in Some Amorphous Solids.- Observation of Direct Interaction between Low-Energy Excitations in Glasses.- Virtual Phonon Exchange in Glasses.- Influence of Phase Separation on the Thermal Conductivity of Potassium Borosilicate Glasses between 1K and 10K.- Influence of OH Content on the Specific Heat and Thermal Conductivity of Vitreous Silica below 1 Kelvin.- The Thermal Conductivity and Diffusivity of Epoxy-Resin from 2 to 80K.- Very Low Frequency Raman Scattering of Glasses.- Brillouin Scattering Study of Thermal Phonons in Crystal Quartz, Fused Quartz, and Borosilicate Glass at Low Temperature.- Discussion on Amorphous Systems.- Magnetic Ions and Molecular Defects.- Spin-Phonon Interactions (invited paper).- Phonon Scattering Induced by Jahn-Teller Impurities.- Resonance Scattering of Phonons at Trigonal Jahn-Teller Centers.- Multimode Jahn-Teller Effects of Ions in Al2O3.- Defect Scattering of Nearly Monochromatic Acoustic Phonons.- Temperature Dependence of the Acoustic Paramagnetic Resonance Spectra for Cr2+ in MgO and KMgF3.- Stress-Induced Changes in the Acoustic Paramagnetic Resonance of Chromous Ions in Magnesium Oxide.- Ultrasonic Relaxation Studies of Cr2+ in MgO.- Contribution to the Study of 3d4 Ions in Al2O3 and MgO by Low Temperature Thermal Conductivity Measurements under Uniaxial Stress.- Heat Pulse Investigations of MgO:Cr2+.- Thermal Conductivity of Irradiated, Additively-Colored, and Deformed MgO.- Phonon Scattering by Ni3+ Ions in Al2O3.- Determination of the Linear Jahn-Teller Coupling Constant of Ni3+ in Al2O3 by Low Temperature Thermal Conductivity Measurements under Uniaxial Stress.- Phonon Spectroscopy in Al2O3 Doped with Transitional Metal Impurities.- An Investigation of Frequency Crossing Effects in Phonon Scattering by V3+ Ions in Al2O3.- An Investigation of the Point Defect Scattering of Phonons by Minute Concentrations of Cr4+ in Corundum by Thermal Techniques.- A Study of Phonon-Spin Interaction in the System 3d1 in Al2O3.- Temperature Dependence of the Lifetime of 29cm?1 Phonons in Ruby between 3 and 17K.- A Study of Spin-Phonon Interactions by Spin-Relaxation Processes.- Intermediate Lattice Coupling Theory of the Paraelastic and Paraelectric Tunnelling System (XY8).- Phonon Spectroscopy of OH? and Li+ Tunnelling States in Alkali Halides.- Discussion on Magnetic Ions and Molecular Defects.- Co-Operative Magnetism and Critical Phenomena.- Phonons in Co-operative Systems (invited paper).- Ultrasonic Attenuation in Thulium Vanadate at 10 GHz at Liquid Helium Temperatures.- The Thermal Conductivity of Holmium Phosphate, a Strong Ising Antiferromagnet with a Large Hyperfine Interaction.- Thermal Conductivity of PrCl3 from 0.1 to 1K, in Zero and 2.2 Tesla Magnetic Field.- Thermal Conductivity of GdCl3, a Representative Magnetic Insulator.- Spin-Phonon Interactions in Exchange Induced Van Vleck Paramagnets.- Magnetic Field Dependent Thermal Conductivity in FeCl2 and FeBr2.- Attenuation and Dispersion of First Sound Near the Lambda Line of 3He — 4He Mixtures.- Thermal Conductivity of RbCaF3.- Phonon Echoes and Phase Transitions.- Critical Attenuation and Velocity of Surface Waves at Structural Phase Transitions.- Ultrasonic Evidence of Commensurate Domain Structure in Holmium.- Discussion on Co-operative Magnetism and Critical Phenomena.- Free Carriers.- Quantum Oscillation in Transmission of Ballistic Heat Pulse in Bismuth.- Phonon Contribution to the Hall Resistivity in Cadmium.- Phonon Scattering and the Thermopower of Dilute Alloys.- Use of a Phonon Probe to Determine the Magnetic Dependence of the Superconducting Gap.- Temperature Dependence of Electron Mean Free Path in Molybdenum from Ultrasonic Measurements.- Interaction and Scattering of Greater than 2? Phonons with Electrons in Superconducting Sn Films.- Experimental Evidence of Phonon Flux Flow Interaction.- Phonon Induced Structure on Damped Magneto-Absorption of Weakly Polar Semiconductors.- On the Role of Nonelectronic Phonon Processes in Mutual Electron-Phonon Drag.- Phonon Experiments with Weakly Bounded Charge Carriers as Detectors.- Anomaly in the Elastic Properties of Semiconductor under Pressure.- X-Ray Scattering Study of Amplified Phonons in the Presence of Plasmons.- Coupled Plasmon-Phonon Effects in IV-VI Semiconductors.- Anisotropy of Phonon Emission from Hot Electrons in Germanium.- Discussion on Free Carriers.- Localized Holes and Electrons.- Phonon Scattering and Ultrasonic Absorption by Acceptors in Si and Ge (invited paper).- The Effect of Magnetic Field and Uniaxial Stress on the Thermal Conductivity of p-Germanium.- Hole — Phonon Interactions in p-Type InSb by Heat Pulse Experiments.- Ultrasonic Attenuation in p-Type Germanium.- Ultrasonic Attenuation Due to the Neutral Acceptor Indium in Silicon.- Phonon Scattering Due to Deep Acceptors in Semiconductors.- Scattering of Thermal Phonons in P Doped Si.- Discussion on Low Temperature Magnetothermal Conductivity in Lightly Doped Ge(Sb) and Ge(As).- Theory of Ultrasonic Attenuation by Hopping Pairs in n-Ge.- Electron-Phonon Interaction in Lightly and Highly Doped n-Type Germanium.- Discussion on Localized Holes and Electrons.- Anharmonic Effects and Phonon-Phonon Scattering.- Multiphonon Absorption in Alkali Halides.- Raman Scattering Studies of Anharmonicities in Potassium Halides.- Thermal Resistance of Dielectric Crystals at High Temperatures.- Three Phonon Relaxation Times.- Optical-Acoustical Phonon Scatterings in the Lattice Thermal Conductivity of Rock Salt Crystals.- The Thermal Conductivity of Solid Krypton between 2.4 and 39K Determined from Measurements of the Thermal Diffusivity with a Heatwave Method.- Discussion on Anharmonic Effects and Phonon-Phonon Scattering.- Defect Scattering and Phonon Focusing.- The Anisotropy of Phonon Propagation in Some Cubic and Trigonal Crystals.- Interface Effects on Phonon Focusing in Rutile.- Conical Refraction and Acoustic Activity in Quartz.- Accuracy of the Boundary Relaxation Time Approximation.- Scattering of Phonons by Dislocations in Crystals.- Discussion on Defect Scattering and Phonon Focusing.- New Techniques.- High Frequency Phonon Emission from Superconducting Al-Tunnelling Junctions (invited paper).- Time Reversed Ultrasonic Echoes as an Experimental Tool (invited paper).- X-Ray Diffraction Study of Non-Equilibrium Phonon Distributions in GaAs (invited paper).- Terahertz-Phonon Pulse Generation by Laser (invited paper).- Discussion on New Techniques.- List of Delegates.- Author Index.