This review provides numerical and graphical information about many (but by no means all) of the physical and electronic properties of GaAs that are useful to those engaged in experimental research and development on this material. The emphasis is on properties of GaAs itself, and the host of effects associated with the presence of specific impurities and defects is excluded from coverage. The geometry of the sphalerite lattice and of the first Brillouin zone of reciprocal space are used to pave the way for material concerning elastic moduli, speeds of sound, and phonon dispersion curves. A section on thermal properties includes material on the phase diagram and liquidus curve, thermal expansion coefficient as a function of temperature, specific heat and equivalent Debye temperature behavior, and thermal conduction. The discussion of optical properties focusses on dispersion of the dielectric constant from low frequencies [κ0(300)=12.85] through the reststrahlen range to the intrinsic edge, and on the ass...

Semiconducting and other major properties of gallium arsenide

A new UV submersible spectroradiometer has been employed to determine the diffuse attenuation coefficient for irradiance in the clearest natural waters [K;(X)] with emphasis on the spectral region from 300 to 400 nm. K (X) can be related to the inherent optical properties of pure water, in particular the total absorption coefficient a,,(X) and the molecular scattering coefficient bm(X), by means of equations derived from radiative transfer theory. We present an analysis showing that limiting values of K. (X) can be estimated from aw(X) and vice versa. Published a (X) data, which show discrepancies much larger than their estimated accuracies, are briefly reviewed and then compared, via our analysis, with K, (X) data (our own new and previously published data as well as relevant data of others). This comparative analysis and new data allow a consistent and accurate set of optical properties for the clearest natural waters and for pure fresh water and saltwater to be estimated from 300 to 800 nm.

Optical properties of the clearest natural waters (200–800 nm)

Raman spectroscopy studies of alkali and alkaline earth silicate glasses and melts are reviewed, and the major Raman bands observed are summarized. To realize the full potential of Raman spectroscopy will require a detailed understanding of their vibrational properties in relation to structure. A number of vibrational calculations have been carried out to address this problem. These are briefly summarized, and some limitations of the method are noted. Systematic variations in bulk properties are examined for viscosity and the immiscibility behavior.

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Structural studies of silicate glasses and melts—applications and limitations of Raman spectroscopy

The infrared lattice bands of $\ensuremath{\alpha}$ quartz have been investigated at 297\ifmmode^\circ\else\textdegree\fi{}K from 5 to 37\ensuremath{\mu} in reflection and transmission with polarized light. Previously published measurements of the optical constants do not agree in this spectral range. It is shown that dispersion theory can fit the data within experimental error throughout the range, and accurate values of the dispersion parameters and the optical constants are obtained. This is the first accurate dispersion analysis of a complex spectrum. A study was made of the accuracy of the Kramers-Kronig method of analysis on this spectrum. The strength, width, and frequency of 14 optically active lattice vibrations are given, 4 of which have not previously been established. From a consideration of published Raman data, 10 of the resonances are assigned according to symmetry type as fundamental vibrations.

Infrared Lattice Bands of Quartz

Since approximately 1950 an increasing portion of experimental solid state physics research has been concerned with studying defects in crystals. This trend might appear to be a rather belated recognition that most of the materials we come into contact with have a random structure. In fact the theoretical understanding and controlled preparation of compounds with defects or random structure has been very slow in developing. The present paper examines and reviews our knowledge of the lattice vibrations associated with defects. The coverage is extremely broad, as shown by the table of contents. It includes localized and resonant modes of isolated defects as well as the modes in highly disordered mixed crystals and glasses. It is primarily a review of experimental work but theoretical results are included where the latter explain or predict significant features. In order to be self-contained several sections of the paper deal entirely with theoretical matters. There is a chapter on explicit solutions of the linear chain vibration problem and a short chapter on Green's function methods. The review emphasizes the infrared absorption and Raman scattering of defects. This is simply because other techniques have not yielded nearly so much information. Neutron scattering and electron tunneling are referred to only where they have shed light on certain systems. Extensive tables of defects and mode frequencies are included for each type of solid. The major solids which are reviewed include semiconductors, ionic compounds, organic compounds, and amorphous insulators.

Optical studies of the vibrational properties of disordered solids

Infrared lattice reflection spectra of III–V compound semiconductors

Raman spectra of vitreous silica, germania and sodium silicate glasses

Laser calorimetric or thermal rise techniques are useful for the determination of very low absorption coefficients in solids. A number of improvements in this technique are described of which the most important is a means of separating surface and bulk absorption. These techniques have been applied to study alkali halides in the ir but are applicable where laser sources of sufficient power are available.

Measurement of very low absorption coefficients by laser calorimetry.

Infrared lattice vibration studies of polar character in compound semiconductors

The production and properties of sheet infrared transmission polarizers of the parallel wire-grating type are discussed. These polarizers are produced by evaporation of a metal conductor on one side of the grooves of an infrared-transmitting plastic film echelette diffraction grating and were first described by Bird and Parrish in 1960. The principal advance in technique given here lies in the use of a commercially available plastic film grating (which is the critical component) and in the fabrication of film gratings of polyethylene which have fewer absorption bands. The degree of polarization is above 98% and the transmission is above 70% in most of the spectral region between 50 cm−1 and 600 cm−1. In the region from 600 cm−1 to 5000 cm−1, the degree of polarization is above 95%, but some plastic absorption bands limit the coverage.

Marvin Hass

Papers

Infrared lattice reflection spectra of III–V compound semiconductors

Raman spectra of vitreous silica, germania and sodium silicate glasses

Measurement of very low absorption coefficients by laser calorimetry.

Infrared lattice vibration studies of polar character in compound semiconductors

Sheet infrared transmission polarizers