Physical Acoustics V6

Physical Acoustics: Principles and Methods, Volume VI provides five chapters covering the whole of physical acoustics. The first chapter extends the methods for studying high frequency sound waves in the hypersonic range by the technique of Brillouin scattering. The next chapter discusses the acoustic properties of materials of the perovskite structure. These materials have ""soft"" modes, which are transverse optic modes of the phonon spectrum that have unusually low and strongly temperature dependent frequencies. This chapter expounds the influence of the soft modes, with particular attention to potassium tantalate and strontium titanate. The third chapter gives a theoretical treatment of the properties and possibilities of surface waves in crystals that are becoming of increasing interest for delay lines, amplifiers of sound waves, and other practical applications. The fourth chapter discusses the experimental methods and results of the dynamic shear properties of solvents and polystyrene solutions from 20 to 300 MHz, including a description of its materials and steady-flow properties. The final chapter deals with condensed helium, which requires quantum reactions to account for its properties. While the experimental data on solid helium are still insufficient, this chapter gives both a theoretical and an experimental account of sound propagation in solid helium, including various liquid forms. This book is recommended to both students and physicists conducting research on physical acoustics.

Contributors

Preface

Contents of Previous Volumes

1 Light Scattering as a Probe of Phonons and Other Excitations

I. Introduction

II. Theory

III. Experimental Apparatus and Techniques

IV. Brillouin Experiments as an Extension of Ultrasonics

V. Brillouin Scattering in the Study of Phase Transitions

VI. Phonon Interactions with Other Excitations

VII. Scattering from Other than Acoustic Phonons

VIII. Stimulated Scattering of Light

References

2 Acoustic Properties of Materials of the Perovskite Structure

I. Introduction

II. Ferroelectricity and Lattice Dynamics

III. Theory of Ultrasonic Attenuation in Soft-Mode Materials

IV. Potassium Tantalate

V. Strontium Titanate

VI. Suggestions for Further Work

References

3 Properties of Elastic Surface Waves

I. Introduction

II. Formulation of the Problem

III. Isotropic Substrates

IV. Iterative Search Procedures

V. Calculated Results

VI. Piezoelectric Effects

VII. Energy Flow

VIII. Pseudosurface Waves

References

4 Dynamic Shear Properties of Solvents and Polystyrene Solutions from 20 to 300 MHz

I. Introduction

II. Experimental Methods

III. Materials and Steady-Flow Properties

IV. Results

References

5 The Propagation of Sound in Condensed Helium

I. Introduction

II. Theory of Sound Propagation in Superfluids

III. 4He

IV. Propagation of Sound in 3He-4He Solutions

V. The Lambda Transition

VI. 3He

VII. Solid Helium

Appendix

References

Author Index

Subject Index