Optical Studies in Liquids and Solids

ISBN-13: 9781468487268 / Angielski / Miękka / 2014 / 266 str.

Skobel'tsyn Academician D V; D. V. Skobel Tsyn

Opis

The study of the vibrations of polyatomic molecules has recently turned into one of the most widespread and powerful methods of studying molecular structure. These vibrations ap- pear directly in the infrared absorption spectra and Raman spectra of gases, liquids, and solids. A measurement of the number of bands in addition to their positions (frequencies or wavelengths) offers the possibility of obtaining a great deal of important information regarding the geometric and mechanical properties of the molecules, the types of chemical bonds, and so forth. It is now quite difficult to list the vast number of specific problems solved by measuring vibrational fre- quencies. As a result of the successful development of research methods and the widespread applica- tion of vibrational spectra in analyzing the structures of molecules and the constitution of ma- terials, it now becomes necessary to develop the theory of molecular vibrations further. Existing theory, of course, is based on the assumption of the harmonicity of molecular vi- brations, which, strictly speaking, is not justified experimentally. The anharmonicity of the molecular vibrations has therefore to be taken into account by introducing appropriate approxi- mations. Thus, in carrying out calculations on the vibrations of polyatomic molecules, one uses the force constants calculated from the observed frequency values. However, as a result of the anharmonicity of the vibrations, the values of the observed frequencies differ from the harmonic values, and the force constants used therefore differ from the true ones, i. e.

Spis treści

Study of Second-Order Lines in the Vibrational Spectra of Molecules.- I. Review of Literature and Presentation of the Problem.- II. Experimental Method.- 1. Study of Second-Order Lines in the Raman Spectra of Liquids.- 2. Study of Infrared Absorption Spectra.- 3. Calculation of the Anharmonicity Coefficients of the Molecular Vibrations.- III. Experimental Results.- 1. Second-Order Lines in the Raman Spectrum of Deute rocyclohexane.- 2. Study of Overtones and Composite Frequencies in the Vibrational Spectra of Benzene and Hexadeuterobenzene.- 3. Second-Order Vibrational Spectra of Chloroform and Deuterochloroform.- 4. Anharmonicity of Some Characteristic Molecular Vibrations.- IV. Discussion of Results and General Conclusions.- 1. General Conclusions Regarding the Anharmonicity Coefficients.- 2. Electro-Optical Parameters of Second-Order Lines.- 3. Use of Anharmonicity Coefficients for Finding the Zero Vibration Frequencies.- Conclusion.- Literature Cited.- Study of the Rotational Oscillation of Molecules in Liquids by the Raman Method.- I. Review of Literature.- 1. Review of Experimental Data Relating to the Low-Frequency Vibrational Spectra.- 2. Methods of Interpreting Low-Frequency Spectra.- 3. Presentation of the Problem.- II. Methods of Obtaining and Analyzing Low-Frequency Raman Spectra.- III. Appearance of the Rotational Oscillations of Methyl Groups in Low-Frequency Raman Spectra.- 1. Experimental Results on the Low-Frequency Raman Spectra of Methyl-Substituted Cyclohexanes.- 2. Referring the Lines in the Raman Spectra of Methyl-Substituted Cyclohexanes to Rotational Oscillations.- IV. Appearance of the Rotational Oscillations of Ethyl and Heavier Groups in the Low-Frequency Raman Spectra.- 1. Experimental Results on the Low-Frequency Raman Spectra of Methyl-Substituted Butanes.- 2. Experimental Results on the Low-Frequency Raman Spectra of Methyl-Substituted Pentanes.- 3. Experimental Results on the Low-Frequency Raman Spectra of Ethyl-Substituted Naphthenes.- Conclusion.- Literature Cited.- Study of the Optical and Electrical Properties of Certain Fourth-Group Metals.- I. Theoretical Study of the Optical Properties of Metals.- 1. Classical Theory of the Skin Effect.- 2. Anomalous Skin Effect.- 3. Frequency of Electron Collisions.- 4. Quantum Kinetic Equation.- II. Measuring Method.- 1. Method of Measuring Optical Constants.- 2. Experimental System for Measuring Optical Constants.- 3. Measurement of the Real and Imaginary Parts of the Complex Refractive Indices n and H.- 4. Possible Systematic Errors.- 5. Samples for Optical Investigations.- 6. Measurement of the Thickness, Density, Conductivity, Critical Temperature, and Hall Effect.- III. Results of the Measurements.- 1. Results of Measuring the Optical Constants of Tin.- 2. Results of Measuring the Optical Constants of Lead.- 3. Effect of Oxidation and Annealing on Optical Constants.- 4. Results of Measuring the Density, Conductivity, Critical Temperature, and Hall Effect of Tin.- 5. Results of Measuring the Density, Conductivity, Critical Temperature, and Hall Effect of Lead.- IV. Analysis of Experimental Results.- 1. Obtaining Micro characteristics.- 2. Micro-Characteristics of Tin.- 3. Micro-Characteristics of Lead.- 4. Character of the Skin Effect for Tin and Lead.- 5. Concentration of Conduction Electrons.- 6. Experimental Proof of the Gurzhi-Holstein Theory.- 7. Velocity of Electrons on the Fermi Surface and Other Microcharacteristics.- 8. Effect of Interelectron Collisions on the Optical Constants of Tin and Lead.- 9. Separation of the Effects of Interband Transitions.- Conclusion.- Literature Cited.- Study of the Spectrum of the Thermal and Stimulated Molecular Scattering of Light in Liquids.- I. State of Theoretical and Experimental Knowledge Regarding the Spectral Composition of the Molecular Scattering of Light.- 1. Scattering of Light at Fluctuations of Anisotropy in Liquids (Thermal Scattering).- 2. Fine Structure of the Molecular-Scattering Lines of Liquids.- 3. Mandelshtam—Brillouin Stimulated Scattering.- II. Theory of the Spectral Composition of the Depolarized Scattering of Light in Liquids.- 1. Relation Between the Spectral Composition of the Scattered Light and the Rotational Thermal Motion of the Molecules in the Liquid.- 2. Effect of Rotational Diffusion of Molecules on the Spectral Composition of the Depolarized Scattering of Light.- 3. Modulation of Scattered Light by the Rotational Oscillations of the Molecules in a Liquid.- 4. Stimulated Scattering of Light on the Wing of the Rayleigh Line.- III. Methods of Studying the Spectral Composition of Scattered Light.- 1. Method of Studying the Spectral Composition of the Wing of the Rayleigh Line (Ordinary Thermal Scattering).- 2. Experimental Apparatus for Studying the Fine-Structure Components of the Rayleigh Line (Thermal Scattering).- 3. Method of Studying the Stimulated Scattering of Light.- IV. Results of an Experimental Study of the Spectrum of Depolarized Scattered Light in Low-Viscosity Liquids.- 1. General Characteristics of the Spectrum of the Depolarized Scattering of Light. Diffusion Wing of the Rayleigh Line.- 2. Results of a Study of the High-Frequency Part of the Rayleigh-Line Wing in Low-Viscosity Liquids at Room Temperature.- 3. Study of the Remote Region of the Rayleigh-Line Wing in Liquids at Various Temperatures.- V. Determination of the Velocity and Absorption of Hypersound in Liquids from the Width of and Spacing Between the Mandelshtam-Brillouin Components.- 1. Measured Values of the Absorption and Velocity of Hypersound.- 2. Analysis of the Results from the Point of View of the Phenomenological Relaxation Theory.- 3. Analysis of the Results from the Point of View of the Molecular Theory of Relaxation.- 4. Intensity Ratio of the Fine-Structure Components.- VI. Stimulated Molecular Scattering of Light.- 1. Stimulated Mandelshtam—Brillouin Scattering in Liquids and Glasses.- 2. Results of an Investigation into the Stimulated Scattering of Light on the Wing of the Rayleigh Line.- Literature Cited.- Gamma- and Photoluminescence of Alkali Iodides.- I. Presentation of the Problem.- II. Study of ?-Luminescence in Alkali Iodides.- 1. Review of Published Data Relating to the Spectral Characteristics of Alkali Iodides.- 2. Choice of Subjects for Study.- 3. Method of Studying the ?-Luminescence Spectra of Alkali Iodides.- 4. Effect of Foreign Impurities on the Unactivated Fluorescence of Alkali Iodides.- 5. Effect of Structural Defects in the Crystals on the Unactivated Luminescence.- 6. Temperature Behavior of the Activator Emission Bands of Phosphors.- 7. Thermoluminescence of Alkali Iodides.- III. Study of the Spectral Characteristics of the Photoexcitation of Phosphors Based on Alkali Iodides.- 1. Review of Published Data Relating to the Absorption of Alkali Halides.- 2. Method of Studying Excitation Spectra.- 3. Experimental Results. Photoexcitation Spectra of the Ultraviolet Fluorescence of Alkali Iodides.- 4. Photoexcitation Spectra of the Intermediate Emission Band of Alkali Iodides.- 5. Photoexcitation Spectra of Alkali Iodides Subjected to Heat Treatment.- 6. Photoexcitation of the Activator Fluorescence of Phosphors Based on Alkali Iodides.- IV. Concentration Dependence of the Time Characteristics of the Phosphors CsI-Tl and KI-Tl.- 1. Attenuation Time of CsI—Tl and KI—Tl Phosphors as a Function of Activator Concentration.- 2. Concentration Dependence of the Growth Time of Scintillations in a Number of CsI—Tl and KI—Tl Phosphors.- V. Discussion of Results.- 1. Discussion of the Nature of the Fluorescence in the Ultraviolet Emission Band of Pure Alkali Iodides.- 2. Discussion of the Nature of the Fluorescence in the Intermediate Emission Band of Alkali Iodides.- 3. Discussion of the Mechanism of Energy Transfer from the Main Substance to the Activator.- Conclusion.- Literature Cited.