Front Cover; Progress in Low Temperature Physics, Volume VI; Copyright Page; Contents; Chapter 1. Intrinsic Critical Velocities in Super-Fluid Helium; 1. Introduction; 2. General Aspects of a Theory of Thermally Activated Processes in Superfluids; 3. Experimental Study of Superfluid Flow States; 4. Specific Models; Chapter 2. Third Sound; 1. Summary; 2. Historical Survey; 3. Theory of Third Sound on Thick Films; 4. Experimental Results for Thick Films; 5. Third Sound on a Moving Film; 6. Theory of Third Sound on Very Thin Films; 7. Experimental Results for Very Thin Films

8. The Average Superfluid Density9. The Onset Thicknesses; 10. Attenuation; Chapter 3. Experimental Properties of Pure He3 And Dilute Solutions of He3 in Superfluid He4 at Very Low Temperatures. Application to Dilution Refrigeration; 1. Introduction; 2. Experimental Properties of Pure Liquid He3 at Very Low Temperatures; 3. Experimental Properties of Dilute Solutions of He3 in He4 at Very Low Temperatures; 4. The Temperature Scale; 5. Dilution Refrigeration in the Millidegree Range; Chapter 4. Pressure Effects in Superconductors; 1. Introduction; 2. Thermodynamics

3. Connection with Microscopic Theory4. Experimental Methods; 5. Experimental Results at Moderate Pressures; 6. Work at Very High Pressures; 7. Pressure Effects in Type II Superconductors; Chapter 5. Superconductivity in Semiconductors and Semi-Metals; 1. Introduction; 2. Semiconducting Properties; 3. Superconducting Properties; 4. Theoretical Analysis of Tc; 5. Conclusion; Chapter 6. Superconducting Point Contacts Weakly Connecting two Superconductors; 1. Introduction; 2. Two Superconductors Weakly Connected by a Single Superconducting Point Contact (the ac Josephson Effect)

3. The Critical Current Through a Double Point Contact Between Two Superconductors as a Function of the Applied Magnetic Field4. Two Superconductors Weakly Connected by a Double Point Contact in the Resistive-Superconductive Region; Chepter 7. Superconductivity above the transition temperature; 1. Introduction; 2. Amorphous Superconductors; 3. Experiments on Amorphous Bismuth, Gallium and Lead Films; 4. Fluctuation Theories; Agreement with Amorphous Film Experiments; 5. Additional Experimental and Theoretical Results; 6. Critical Fluctuation Region; 7. Conclusion

8. Chronology and Acknowledgments9. Appendix. Details of Amorphous Film Experiments; Chapter 8. Critical Behaviour in Magnetic Crystals; 1. Introduction; 2. Susceptibility of Ferromagnets Above the Critical Temperature; 3. Spontaneous Magnetization; 4. Specific Heat; 5. Conclusion; Chapter 9. Diffusion and Relaxation of Nuclear Spins in Crystals Containing Paramagnetic Impurities; Introduction; 1. Direct Nuclear Relaxation by Magnetic Ions; 2. Spin Diffusion; 3. Nuclear Relaxation When Spin Diffusion is Taken into Account; 4. Nonexponential Relaxation