Lecture notes on equilibrium point defects and thermophysical properties of metals 7. Electrical resistivity of metals. 7.1. Influence of point defects on electrical resistivity. 7.2. Resistivity of metals at high temperatures. 7.3. Quenched in resistivity. 7.4. Comparison of data from two methods. 7.5. Summary 8. Positron annihilation. 8.1. Positron annihilation techniques. 8.2. Experimental data. 8.3. Drawbacks of positron annihilation techniques. 8.4. High vacancy concentrations in some intermetallics. 8.5. Summary 9. Other methods. 9.1. Hyperfine interactions. 9.2. Other physical properties. 9.3. Microscopic observation of quenched in defects. 9.4. Summary 10. Equilibration of point defects. 10.1. Role of internal sources (sinks) for point defects alloys and intermetallics. 10.2. Electrical resistivity. 10.3. Specific heat. 10.4. Positron annihilation. 10.5. Equilibration times from relaxation data. 10.6. Summary 11 . Parameters of vacancy formation. 11.l. Equilibrium concentrations of point defects. 11.2. Point defects in high melting point metals. 11.3. Temperature dependence of formation parameters. 11.4. Summary 12. Discussion. 12.1. Comparison of experimental techniques. 12.2. Critical vacancy concentrations. 12.3. Thermodynamic bounds for formation entropies. 12.4. Effects of anharmonicity. 12.5. Constant volume specific heat of tungsten. 12.6. Thermal defects in alloys and intermetallics. 12.7. Self diffusion in metals. 12.8. Point defects and melting. 12.9. How to determine vacancy contributions to enthalpy a proposal. 12.10. Summary 13. Conclusions. 13.1. Current knowledge of equilibrium point defects in metals. 13.2. Actuality of Seegers formulation. 13.3. What could be done to reliably determine equilibrium defect concentrations. Despite the significant progress in the study of point defects in metals some important problems still do not have unambiguous solutions. One of the most practically important questions relates to equilibrium defect concentrations. There exist two opposite viewpoints: (1) defect contributions to physical properties of metals at high temperatures are small and cannot be separated from the effects of anharmonicity; the equilibrium defect concentrations at the melting points are in the range of 10 4 to 10 3; (2) in many cases defect contributions to the specific heat of metals are much larger than nonlinear effects of anharmonicity and can be separated without crucial errors; the equilibrium concentrations at the melting points are of the order of 10 3 in low melting point metals and 10 2 in high melting point metals. This book discusses the experimental results and theoretical considerations favoring each claim. At present the majority of the scientific community hold the first viewpoint. Regrettably the data supporting the second viewpoint have never been displayed and discussed together and the criticism of this viewpoint has never included a detailed analysis. Important arguments supporting this viewpoint have appeared in the last decade. It may turn out that just calorimetric determinations provide the most reliable values of equilibrium defect concentrations in metals. In this book the main attention is paid to equilibrium point defects in metals and their relation to thermophysical properties of metals. Along with a discussion on experimental data and theoretical estimates now available some approaches are proposed that seem to be most suitable for settling the question 1. Introduction. 1.1. Point defects in solids. Formation parameters. 1.2. Influence of point defects on physical properties. 1.3. Strong nonlinear increase in specific heat. 1.4. Two viewpoints on equilibrium point defects in metals 2. Basic theory of point defect formation. 2.1. Thermodynamics of point defect formation. 2.2. Origin of the formation entropy. 2.3. Temperature dependence of formation parameters. 2.4. Results of theoretical calculations. 2.5. Summary 3. Methods for studying point defects. 3.1. Measurements in equilibrium. 3.2. Quenching experiments. 3.3. Observation of vacancy equilibration. 3.4. Summary 4. Modulation calorimetry and related techniques. 4.1. Introduction. 4.2. Basic theory of modulation calorimetry. 4.3. Modulation of heating power. 4.4. Measurement of temperature oscillations. 4.5. Modulation dilatometry. 4.6. Modulation measurements of electrical resistivity and thermopower. 4.7. Summary 5. Enthalpy and specific heat of metals. 5.1. Point defects and specific heat. 5.2. Methods of calorimetry. 5.3. Formation parameters from calorimetric data. 5.4. Extra enthalpy of quenched samples. 5.5. Question to be answered by rapid heating experiments. 5.6. Specific heat of tungsten a student experiment. 5.7. Summary 6. Thermal expansion of metals. 6.1. Point defects and thermal expansion. 6.2. Methods of dilatometry. 6.3. Differential dilatometry. 6.4. Equilibrium vacancy concentrations. 6.5. High vacancy concentrations in some alloys and intermetallics. 6.6. Lattice parameter and volume of quenched samples. 6.7. Summary.