Showing papers on "Photoacoustic spectroscopy published in 1978"
Book•
11 Apr 1978
TL;DR: A survey of infrared data processing techniques can be found in this paper, where the authors present a survey of the state-of-the-art techniques in infrared spectroscopy, including Fourier Transform Infrared Reflection*b1Absorption Spectroscopy.
Abstract: P.C. Gillette, J.B. Lando, and J.L. Koenig, A Survey of Infrared Spectral Data Processing Techniques. P.L. Polavarapu, Fourier Transform Infrared Vibrational Circular Dichroism. K. Krishnan, Advances in Capillary Gas Chromatography*b1Fourier Transform Interferometry. A.G. Nerheim, Applications of Spectral Techniques to Thermal Analysis. P. Painter, M. Starsinic, and M. Coleman, Determination of Functional Groups in Coal by Fourier Transform Interferometry. J.R. Ferraro and A.J. Rein, Applications of Diffuse Reflectance Spectroscopy in the Far-Infrared Region. J.D. Swalen and J.F. Rabolt, Characterization of Orientation and Lateral Order in Thin Films by Fourier Transform Infrared Spectroscopy. W.G. Golden, Fourier Transform Infrared Reflection*b1Absorption Spectroscopy. J.A. Graham, W.M. Grim III, and W.G. Fateley, Fourier Transform Infrared Photoacoustic Spectroscopy of Condensed-Phase Samples. Each chapter includes references. Index.
163 citations
TL;DR: In this article, the authors applied photoacoustic spectroscopy to studies of surface and subsurface structures of solids, focusing on silicon-nitride ceramic material, which is used for the manufacturing of turbine blades.
Abstract: The new technique of photoacoustic spectroscopy is applied to studies of surface and subsurface structures of solids. In the present case, special attention is focused on silicon‐nitride ceramic material, which is used for the manufacturing of turbine blades. Good correlation is obtained between the observed photoacoustic signal and surface microstructure. In addition, the photoacoustic signal shows inhomogeneities that are not visually detected under a microscope.
155 citations
TL;DR: The exact form of the Rosencwaig Gersho theory for the photoacoustic effect in solids is used to depict how the magnitude and phase of the photoACoustic signal vary with chopping frequency and normalized length.
Abstract: The exact form of the Rosencwaig‐Gersho theory for the photoacoustic effect in solids is used to depict how the magnitude and phase of the photoacoustic signal vary with chopping frequency and normalized length. Applications of the theory to studies of film‐substrate systems are discussed.
88 citations
65 citations
TL;DR: In this article, the time-dependent response of photoacoustic cells to pulsed excitation was examined both theoretically and experimentally, and the theoretical treatment included both the response of conventional optical absorbers and absorbers containing metastable states.
Abstract: The time‐dependent response of photoacoustic cells to pulsed excitation is examined both theoretically and experimentally The theoretical treatment includes both the response of conventional optical absorbers and absorbers containing metastable states These results should be useful in dye laser applications of photoacoustic spectroscopy on both absorbing and luminescent materials The experimental results were obtained using a newly developed device in which both electrical heating and optical heating have been shown to produce an equivalent acoustic response This device should have applications in the design and calibration of cells for photoacoustic spectroscopy
62 citations
TL;DR: Among the advantages of photoacoustic spectroscopy, the signal is almost insensitive to light scattering by the sample and information can be obtained about nonradiative deactivation processes.
Abstract: Photoacoustic spectroscopy is a new analytical tool that provides a simple nondestructive technique for obtaining information about the electronic absorption spectrum of samples such as powders, semisolids, gels, and liquids. It can also be applied to samples which cannot be examined by conventional optical methods. Numerous applications of this technique in the field of inorganic and organic semiconductors, biology, and catalysis have been described. Among the advantages of photoacoustic spectroscopy, the signal is almost insensitive to light scattering by the sample and information can be obtained about nonradiative deactivation processes. Signal saturation, which can modify the intensity of individual absorption bands in special cases, is a drawback of the method.
47 citations
TL;DR: In this article, a spectrophone and a CO2 laser source were used to determine the absorption coefficients of NH3 at seventy-seven laser lines in the 00°1-02°0 band at 9.4 μm and the 00 ≥ 1-10° 0 band at 10.4 µm.
Abstract: A spectrophone and a CO2 laser source were used to determine the absorption coefficients of NH3 at seventy-seven laser lines in the 00°1–02°0 band at 9.4 μm and the 00°1–10°0 band at 10.4 μm. The NH3 was buffered with N2 to 1 atm at 295 K; its concentration ranged from 30 ppm to 200 ppm. The absorption coefficients and their probable errors are tabulated.
42 citations
TL;DR: In this paper, a new method for the measurement of the primary fluorescence quantum yield of dye solutions is presented, relying of the S n → S 1 transition probability as an internal standard for comparison with the S 1 radiationless transition probability, both probabilities being measured by photoacoustic spectroscopy.
41 citations
TL;DR: By supporting specimens on a thin membrane in the spectrophone wall, photo-acoustic spectroscopy can be made on objects outside the acoustic chamber as mentioned in this paper, where the conditions under which the technique may become practicable are briefly discussed.
37 citations
TL;DR: In this paper, the authors report on the spectroscopy and energetics of several preparations of the purple membrane from Halobacterium halobium, which is well established that this membrane contains a single protein, bacteriorhodopsin, covalently bound to a retinal molecule.
32 citations
TL;DR: Gray et al. as discussed by the authors applied photoacoustic spectroscopy applied to systems involving photoinduced gas evolution or consumption, and showed that the spectrogram can be used to estimate the gas evolution and consumption.
Abstract: Analytical Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Photoacoustic spectroscopy applied to systems involving photoinduced gas evolution or consumption Robert C. Gray, and Allen J. Bard Anal. Chem., 1978, 50 (9), 1262-1265• DOI: 10.1021/ac50031a018 • Publication Date (Web): 01 May 2002 Downloaded from http://pubs.acs.org on February 16, 2009
TL;DR: In this article, the construction and operation of a Michelson interferometer that permits Fourier transform photoacoustic spectroscopy of opaque and partially transparent samples at visible wavelengths is described.
Abstract: The construction and operation of a Michelson interferometer that permits Fourier transform photoacoustic spectroscopy of opaque and partially transparent samples at visible wavelengths is described. Multiplexing and throughput advantages are considered. A visible spectrum of Nd(III) doped laser glass is reproduced and potential kinetic applications are described.
TL;DR: In this paper, photoacoustic spectroscopy (PAS) was used for studying surfaces and adsorbed species in the visible region of the spectrum, where the information obtainable is much more detailed and specific.
Abstract: Rosencwaig pointed out that the recently revived technique of photoacoustic spectroscopy (PAS)1 should be useful for studying surfaces and adsorbed species, and demonstrated the feasibility of the approach by recording some spectra in the visible region of the spectrum.2 It would, however, be more useful to be able to obtain spectra of adsorbed species in the IR range because the information obtainable is much more detailed and specific (the greater utility of IR than UV-visible spectra is amply demonstrated by the extensive
TL;DR: In this paper, photoacoustic spectroscopy is used to obtain dichroism spectra of strongly absorbing samples and the effects, natural or magnetically induced, are recorded with a scale directly comparable to that of the absorption data.
Abstract: Photoacoustic spectroscopy is used to obtain dichroism spectra of strongly absorbing samples. The effects, natural or magnetically induced, are recorded with a scale directly comparable to that of the absorption data. The validity of the experiments has been examined using conventional dichroism and absorption techniques on a thin slice of a NdMoO4 crystal.
TL;DR: Simple cells are described for normal and differential measurements in photoacoustic spectroscopy and the arrangement allows great flexibility in cell design for adaptation to special sample forms.
Abstract: Simple cells are described for normal and differential measurements in photoacoustic spectroscopy. The differential cell allows for easy background signal correction and for comparison of related samples. The arrangement allows great flexibility in cell design for adaptation to special sample forms. The normal cell can be used for very small volumes, liquids as well as solids, and is constructed in such a way as to allow the possibility of Helmholtz resonance to occur over a range of frequencies. The two cells are compared in terms of background and maximal signal strength and examples of spectra obtained with each of them are given. The general spectrometer setup is outlined as well.
TL;DR: In this article, the dominant decay mode for Cr 3+ in MgO is shown to be quite different from that found in ruby, and it is possible to identify dominant modes of radiationless relaxation of ions in crystals by comparing photoacoustic spectra with fluorescence excitation spectra.
TL;DR: In this article, the vibronic sideband of the major zero-phonon line was analyzed with a computer iteration process to determine one-and multiphonon contributions.
Abstract: Several zero-phonon lines are observed in the fluorescence spectrum at low temperatures and annealing experiments show that these are associated with aggregation of Eu2+-K+ vacancy pairs. Time-resolved spectroscopy measurements show that energy transfer takes place from ions in non-aggregated sites to those in aggregated centres. The time dependence is consistent with resonant electric dipole-dipole interaction with no back-transfer taking place. The vibronic sideband of the major zero-phonon line is analysed with a computer iteration process to determine one-phonon and multiphonon contributions. The thermal dependence of the width and position of the major zero-phonon line is shown to be consistent with strong coupling to only the low-frequency phonon modes. Non-radiative decay processes at room temperature are characterised by comparing fluorescence excitation and photoacoustic spectra.
TL;DR: In this paper, a simple and efficient way to enhance the photoacoustic signal from solid or powder samples is described, and the increase in signal is found to be related mainly to the diffusivity and the ratio of specific heats of the gas which is used to couple the heat variation at the sample surface to the microphone detector.
Abstract: A simple and efficient way to enhance the photoacoustic signal from solid or powder samples is described. The increase in signal is found to be related mainly to the diffusivity and the ratio of specific heats of the gas which is used to couple the heat variation at the sample surface to the microphone detector. The measured signal enhancement on various powder samples agrees fairly well with the one‐dimensional theory by Rosencwaig and Gersho. The effect of physical adsorption of gas by the sample is also examined.
TL;DR: In this paper, photoacoustic spectroscopy has been used to study TII powders used in thin film coating applications, and the spectra obtained show differences between what was regarded as good coating material from that which was unacceptable.
Abstract: Photoacoustic spectroscopy has been used to study TII powders used in thin film coating applications. The spectra obtained show differences between what was regarded as good coating material from that which was unacceptable. Good material displayed a sharp absorption edge at 440 nm and no tailing off at the transparent side of the edge. The ratio of signals on the opaque side of the edge divided by that on the transparent side was largest for good material. Much of the poorer material contained absorbed I2 within the material. It was found that material exposed to the atmosphere would evolve I2 gas. Differenence spectra between freshly mounted T1I and evolved materials closely resemble absorption spectra of I2 gas.
TL;DR: In this paper, a 7mm thick, 18mm diameter disc-shaped sample of BiI3 was used for optically characterizing bismuth tri-iodide, which has been used in antireflective thin film coatings on potassium chloride laser windows.
Abstract: We found a need to optically characterize bismuth tri-iodide, BiI3, which has been used in antireflective thin film coatings on potassium chloride laser windows. We received a 7mm thick, 18mm diameter disc shaped sample of BiI3 which exhibited a dark gray, glassy, metallic appearance. Several commercial spectrophotometers in the laboratory showed it to be opaque from 0.3μm to 50μm. We therefore decided to see if relevant optical data could be obtained on the sample using an in-house built photoacoustic spectrometer.
01 Jan 1978
TL;DR: In this article, the use of photoacoustic spectroscopy (PAS) to obtain information about the electronic absorption spectra of organometallic compounds is described, which is used to investigate the optical properties of: (a) several quasi-one-dimensional rhodium metal complexes and (b) several transition metal catalysts which are immobilized on polymeric microsphere substrates.
Abstract: The use of photoacoustic spectroscopy (PAS) to obtain information about the electronic absorption spectra of organometallic compounds is described. PAS is used to investigate the optical properties of: (a) several quasi-one-dimensional rhodium metal complexes and (b) several transition metal catalysts which are immobilized on polymeric microsphere substrates. The PAS spectra reveal dramatic differences between highly conducting rhodium, polymeric chains and dimeric (and nonconducting) rhodium complexes. For the catalysts, the photoacoustic spectra provide information concerning the degree of reductionof the transition metal and metal-ligand interactions which correlate with catalytic behavior.
16 May 1978
TL;DR: In this paper, an extensive investigation of the spectroscopic properties of Nd(x)Y(1-x)P5O14 is reported, and a new quenching model for neodymium pentaphosphate crystals based on spatial but non-spectral energy migration to surface quench sites is proposed.
Abstract: : An extensive investigation of the spectroscopic properties of Nd(x)Y(1-x)P5O14 is reported. Time-resolved site-selection spectroscopy and photoacoustic spectroscopy techniques were used as well as standard optical spectroscopy measurements which were made as a function of Nd concentration, temperature, excitation wavelength and laser power. Results show that Nd ions occupy a variety of slightly perturbed sites. No significant energy transfer appears to be taking place between ions in these inequivalent sites. Additional experimental data presented here suggests a new quenching model for neodymium pentaphosphate crystals based on spatial but non-spectral energy migration to surface quenching sites. (Author)