Optical Studies in Liquids and Solids

Optical Studies in Liquids and Solids PDF Author: D. V. Skobel tsyn
Publisher: Springer Science & Business Media
ISBN: 1468487248
Category : Science
Languages : en
Pages : 270

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Book Description
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.

Optical Studies in Liquids and Solids

Optical Studies in Liquids and Solids PDF Author: D. V. Skobel tsyn
Publisher: Springer Science & Business Media
ISBN: 1468487248
Category : Science
Languages : en
Pages : 270

Get Book

Book Description
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.

Optical Studies in Liquids and Solids

Optical Studies in Liquids and Solids PDF Author: Lebedev Physics Institute
Publisher:
ISBN:
Category :
Languages : en
Pages : 263

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Book Description


Optical Properties of Solids

Optical Properties of Solids PDF Author: Frederick Wooten
Publisher: Academic Press
ISBN: 1483220761
Category : Science
Languages : en
Pages : 273

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Book Description
Optical Properties of Solids covers the important concepts of intrinsic optical properties and photoelectric emission. The book starts by providing an introduction to the fundamental optical spectra of solids. The text then discusses Maxwell's equations and the dielectric function; absorption and dispersion; and the theory of free-electron metals. The quantum mechanical theory of direct and indirect transitions between bands; the applications of dispersion relations; and the derivation of an expression for the dielectric function in the self-consistent field approximation are also encompassed. The book further tackles current-current correlations; the fluctuation-dissipation theorem; and the effect of surface plasmons on optical properties and photoemission. People involved in the study of the optical properties of solids will find the book invaluable.

Optical Properties of Highly Transparent Solids

Optical Properties of Highly Transparent Solids PDF Author: Bernard Bendow
Publisher: Springer Science & Business Media
ISBN: 1468421786
Category : Science
Languages : en
Pages : 525

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Book Description
Although much work has been performed on measure ments and interpretation of light absorption by opaque or nearly opaque solids, it is surprising to note that until recently relatively little reliable experimental data, and much less theoretical work was available on the nature of transparent solids. This, in spite of the fact that a vast majority of engineering and device ap plications of a solid depend on its optical transparency. Needless to say, all solids are both transparent and opa que depending on the spectral region of consideration. The absorption processes that limit the transparency of a solid are either due to lattice vibrations, as in ionic or partially ionic solids, or due to electronic transi tions, both intrinsic and impurity-induced. For most materials, a sufficiently wide spectral window exists be tween these two limits, where the material is transpar ent. In general, the absorption coefficient, in the long wavelength side of, but sufficiently away from, the fun damental absorption edge, is relatively structureless and has an exponential dependence on frequency. Recent evi dence suggests that in the short wavelength side of the one-phonon region, but beyond two- or three-phonon sin gularities, the absorption coefficient of both polar and nonpolar solids is also relatively structureless and de pends exponentially on frequency.

Optical Properties of Excited States in Solids

Optical Properties of Excited States in Solids PDF Author: Baldassare di Bartolo
Publisher: Springer Science & Business Media
ISBN: 146153044X
Category : Science
Languages : en
Pages : 749

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Book Description
This book presents an account of the course "Optical Properties of Excited States in Solids" held in Erice, Italy, from June 16 to 3D, 1991. This meeting was organized by the International School of Atomic and Molecular Spectroscopy of the "Ettore Majorana" Centre for Scientific Culture. The purpose of this course was to present physical models, mathematical formalisms and experimental techniques relevant to the optical properties of excited states in solids. Some active physical species, such as ions or radicals, could survive indefinitely if they were completely 'isolated in space. Other active species, such as excited molecular and solid-state systems, are inherently unstable, even in isolation, due to the spontaneous mechanisms that may convert their excitation energies into radiation or heat. Physical parameters that may be used to characterize these excited systems are the localization or delocalization, and the coherence or incoherence, of their state excitations. In solids the excited states, whether they are localized (as for impurities in insulators) or delocalized (as they may occur in semiconductors), are relevant in several regards. Their de-excitation is extremely sensitive to the nature of the excitations of the systems, and a study of the de-excitation processes can yield a variety of information. For example, the excited states may represent the initial condition of the onset of such processes as Stokes-shifted emission, hot luminescence, symmetry-dependent Jahn-Teller and scattering processes, tunneling processes, energy transfer to like and unlike centers, superradiance, coherent radiation, and excited state absorption.

Perspectives in Materials Research

Perspectives in Materials Research PDF Author: National Research Council (U.S.). Advisory Committee on Perspectives in Materials Research
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 792

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Book Description


Handbook of Optical Constants of Solids

Handbook of Optical Constants of Solids PDF Author: Edward D. Palik
Publisher: Academic Press
ISBN: 0080556302
Category : Science
Languages : en
Pages : 1121

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Book Description
This handbook--a sequel to the widely used Handbook of Optical Constants of Solids--contains critical reviews and tabulated values of indexes of refraction (n) and extinction coefficients (k) for almost 50 materials that were not covered in the original handbook. For each material, the best known n and k values have been carefully tabulated, from the x-ray to millimeter-wave region of the spectrum by expert optical scientists. In addition, the handbook features thirteen introductory chapters that discuss the determination of n and k by various techniques. * Contributors have decided the best values for n and k * References in each critique allow the reader to go back to the original data to examine and understand where the values have come from * Allows the reader to determine if any data in a spectral region needs to be filled in * Gives a wide and detailed view of experimental techniques for measuring the optical constants n and k * Incorporates and describes crystal structure, space-group symmetry, unit-cell dimensions, number of optic and acoustic modes, frequencies of optic modes, the irreducible representation, band gap, plasma frequency, and static dielectric constant

Optical Properties of Thin Solid Films

Optical Properties of Thin Solid Films PDF Author: O. S. Heavens
Publisher: Courier Corporation
ISBN: 0486669246
Category : Science
Languages : en
Pages : 276

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Book Description
Authoritative reference treats the formation, structure, optical properties, and uses of thin solid films, emphasizing causes of their unusual qualities. 162 figures. 19 tables. 1955 edition.

Recent Instrumentation for the Optical Studies of Solids in the Vacuum Ultra-violet

Recent Instrumentation for the Optical Studies of Solids in the Vacuum Ultra-violet PDF Author: Paul Leon Hartman
Publisher:
ISBN:
Category : Optical instruments
Languages : en
Pages : 60

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Book Description
Recent progress in vacuum ultra-violet instrumentation and techniques useful to solid state physics is described, although much of the instrumentation advances are also of use to other V-uv studies. Improvements in sources, detectors, and dispersive systems (particularly in grating reflectivities) are noted. While commercial instrumentation is not described, it is perhaps in this area that the most striking instrumental progress has come. Besides optical studies, work on internal and external photoemission continues to augment the optical work. Interest in luminescent systems is also still useful as indicating something about the energy band scheme in insulating solids. An important advance is noted wherein use is made of laser radiation in conjunction with ultra-violet radiation in a double photon absorption process in KI. (Author).

Optical Absorption and Dispersion in Solids

Optical Absorption and Dispersion in Solids PDF Author: John Noel. Hodgson
Publisher: Springer Science & Business Media
ISBN: 1461333210
Category : Science
Languages : en
Pages : 146

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Book Description
The electromagnetic theory of Maxwell and the electron theory of Lorentz and Drude stimulated a great deal of experimental work on the optical properties of solids in the late nineteenth and early twentieth centuries. The time was not then ripe, however, for general progress in this field. The experimental techniques were not available to produce suitable specimens for optical measurements with well defined structure and purity. On the theoretical side, the classical electron theory provided only a very incomplete account of the interaction of light waves with matter. The centre of interest in optical research moved to atomic and molecular spectroscopy where quantitative results were easier to obtain. The quantum theory, starting with Bohr's theory of 1913, provided a highly successful basis for the interpretation of the optical spectra of atoms and molecules. The present-day theory of the optical properties of solids is based on the quantum theory of electrons in solids, developed from the early researches of Sommerfeld and Bloch, and the theory of lattice vibrations originating in the research by Born. The formal con nection between optical absorption and electron wave functions in solids has been well known since the 1930s but it is only recently that electron energy band calculations have achieved sufficient accuracy to make profitable a comparison of experimental and theoretical results. Without some guidance from a theoretical band structure calculation, it would be difficult to make any progress with the in terpretation of an optical absorption spectrum.