Download or read book The Interaction of Chromium Ions in Ruby Crystals written by Richard C. Powell and published by . This book was released on 1966 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Absorption, excitation, continuous fluorescence, and pulse fluorescence measurements were made on ruby samples with 0.94% and 2.1% Cr+3 in the temperature range from 4.2K up to 700K. The widths, positions, intensities, and lifetimes of the R and N fluorescence lines were determined at numerous temperatures. The results for the temperature dependence of the linewidths are explained in terms of microscopic strains, Raman scattering of phonons by the impurity ions, and direct phonon processes. The results for the lineshifts with temperature are due to the absorption and emission of virtual phonons. The observed lifetimes of the R and N lines coincide in the temperature range where the systems are thermalized and the observed decays are pure exponentials. At temperatures where the systems are decoupled, an initial rise in fluorescence is observed at the N lines. The subsequent decay has the lifetime of the R lines for a 0.94% sample and the lifetime of the N lines for a 2.1% sample. These results are also explained in terms of energy transfer from single ions to pairs. The effects of reabsorption on the fluorescence spectrum are also discussed. (Author).
Download or read book The Interaction of Chromium Ions in Ruby Crystals written by Richard Conger Powell and published by . This book was released on 1966 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Absorption, excitation, continuous fluorescence, and pulse fluorescence measurements were made on ruby samples with 0.94% and 2.1% Cr+3 in the temperature range from 4.2K up to 700K. The widths, positions, intensities, and lifetimes of the R and N fluorescence lines were determined at numerous temperatures. The results for the temperature dependence of the linewidths are explained in terms of microscopic strains, Raman scattering of phonons by the impurity ions, and direct phonon processes. The results for the lineshifts with temperature are due to the absorption and emission of virtual phonons. The observed lifetimes of the R and N lines coincide in the temperature range where the systems are thermalized and the observed decays are pure exponentials. At temperatures where the systems are decoupled, an initial rise in fluorescence is observed at the N lines. The subsequent decay has the lifetime of the R lines for a 0.94% sample and the lifetime of the N lines for a 2.1% sample. These results are also explained in terms of energy transfer from single ions to pairs. The effects of reabsorption on the fluorescence spectrum are also discussed. (Author)
Download or read book Exchange Interaction Between Chromium Ions in Ruby Crystals written by F. J. MILFORD and published by . This book was released on 1962 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: ESCRIPTORS: *Metabolic products, *O OR tor ge, Urine, Control, Materials, Plastics, Disinfecta t, Sa i ry engin ering. Identifiers: Fall-out shelters. Data are pre ented on he storability of human waste in fiber drum containers line ith t ree diff rent plastic films and containing four differe sanitizers, over a period of 14 day . Adequate odor control was achieved with all sanitizers, i.e. soda ash, cresylic aci s, aponified phenols and sodium pentachlorophenate, ALTHOUGH SODA ASH SHOWED NO BAC ERICIDAL ACTION. Cresylic acids appear to be the preferred sani i r. Amo g h liners, vinyl showed poor integrity, polyethylene and polyethylene-cellop a lami a e howed marginal integrity. All plas ics sho ed chemical compatibility it the waste. D- *>+ N5 +++Storage of human wa te in fiber drum lined with polyethylene or vinyl liners. The effects of 4 different disi fec ants on co trol of gas evolution and odor.
Download or read book The Interection of Chromium Ions in Ruby Crystals written by Richard C. Powell and published by . This book was released on 1966 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interaction of Paramagnetic Ions and Aluminum Nuclei in Ruby written by CARL M. VERBER and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: Th techniques of continuous and pulse nuclear magnetic resonance were used to study the aluminum nuclei in ruby crystals. Four commercially prepared samples having nominal chromium ion concentrations of 0.01, 0.1, 1.5, and 4% were investigated at 300, 78, 4, and 1.7 K. The line widths were found to be due to two major contributions. The mutual interaction of the aluminum nuclei contributed a constant broadening of about 7 gauss. The paramagnetic ions contributed a broadening which ranged from 0 to 42 ga ss as a function of temperature, concentration and static magnetic field. This dependence can be calculated by assuming that the chromium ions have an effective magnetic moment which is determined by the Boltzman average of the four spin states of the ion at each temperature considered. This indicates that the chromium ions are in good thermal contact with the lattice down to 1.7 K. The relaxation times were found to be a strong function of the chromium ion concentration. An effort was made to predict these times, using known values of the chromium relaxation times and existing theories in which the nuclear relaxation times are given in terms of the paramagnetic relaxation times. No agreement was found between theoretical and experimental values, and a revision of existing theories is indicated. (Author).
Download or read book Microwave optical Investigations of Cr superscript 3 Pairs in Ruby written by Michael John Berggren and published by . This book was released on 1969 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infrared Absorption of Excited Chromium Ions in Crystals written by Gary King Klauminzer and published by . This book was released on 1970 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exchange Interaction Between Pairs of Chromium Ions in Ruby written by P. Kisliuk and published by . This book was released on 1963 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The temperature dependence of the absorption of the spectral lines due to pairs of chromium ions in concentrated ruby at 7009 and 7041 Angstroms is fitted to theory by assuming isotropic exchange coupling. Other frequencies predicted from the parameters thus determined are identified in the observed spectrum. Higher states are identified by means of the excitation spectrum and the spacings already known from the identification of the lower levels. To a closer approximation, it is found that the ground state splitting can be fitted within the experimental error using isotropic exchange if a biquadratic term is included, in addition to the usual quadratic term. Furthermore, the ratio of the coefficients of these terms is of the same order as that found in other materials and predicted by theory. The excited states, however, do not appear to fit a theory based on isotropic exchange coupling as the sole perturbation. (Author).
Download or read book Exchange coupled Chromium Ion Pairs in Ruby written by Linn Frederick Mollenauer and published by . This book was released on 1965 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1969 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystal Engineering written by Jeffrey H Williams and published by Morgan & Claypool Publishers. This book was released on 2017-09-28 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are more than 20 million chemicals in the literature, with new materials being synthesized each week. Most of these molecules are stable, and the 3-dimensional arrangement of the atoms in the molecules, in the various solids may be determined by routine x-ray crystallography. When this is done, it is found that this vast range of molecules, with varying sizes and shapes can be accommodated by only a handful of solid structures. This limited number of architectures for the packing of molecules of all shapes and sizes, to maximize attractive intermolecular forces and minimizing repulsive intermolecular forces, allows us to develop simple models of what holds the molecules together in the solid. In this volume we look at the origin of the molecular architecture of crystals; a topic that is becoming increasingly important and is often termed, crystal engineering. Such studies are a means of predicting crystal structures, and of designing crystals with particular properties by manipulating the structure and interaction of large molecules. That is, creating new crystal architectures with desired physical characteristics in which the molecules pack together in particular architectures; a subject of particular interest to the pharmaceutical industry.
Download or read book Optical Electronics written by Jixiang Yan and published by Walter de Gruyter GmbH & Co KG. This book was released on 2019-02-19 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses light transmission and extends to more applied fields of laser and laser technology, photoelectric detection and devices, photoelectric imaging and systems with explainations on theories and engineering applications. Addressing the intersection between optics and electrical engineering, the textbook prepares graduate students to photoelectronics and can also be used as reference for engineers.
Download or read book Keywords Index to U S Government Technical Reports written by and published by . This book was released on 1962-12 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Government Research Reports written by and published by . This book was released on 1962 with total page 1166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Temperature Physics written by and published by . This book was released on 1963 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Eighth International Conference on Low Temperature Physics written by R. O. Davies and published by . This book was released on 1963 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Properties of Solids written by Anthony Mark Fox and published by Oxford University Press, USA. This book was released on 2001 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives an introduction to the optical properties of solids, including many new topics that have not been previously covered in other solid state texts at this level. The fundamental principles of absorption, reflection, luminescence and light scattering are discussed for a wide range of materials, including crystalline insulators and semiconductors, glasses, metals, and molecular materials. Classical and quantum models are used where appropriate along with recent experimental data. Examples include semiconductor quantum wells, organic semiconductors, vibronic solid state lasers, and nonlinear optics.
