The oxidation of antimony has been studied between 265 ~ and 385~ The reaction is characterized by an initially parabolic growth rate, which degenerates into a time-independent rate, controlled by the gaseous diffusion of (Sb~O~)~ from the surface region to the cold wall outside the sample furnace. The stationary rate decreases with increasing oxygen pressure and with increasing diffusion length. A compact layer of Sb~O~ forms on the antimony surface and supports a further overgrowth of Sb~O~. Kinetic data have been analyzed to obtain thermochemical parameters for the reaction which yields (Sb~Os)2(g) and agreement is obtained with known data for the equilibrium 2Sb~Os(s) ~ (Sb20~)2(g).Several studies now in progress in these laboratories (1) deal with the oxidation of intermetallic compounds containing antimony as a principal element. To provide a suitable frame of reference, it has been necessary to examine the oxidation of elemental antimony itself. The present article is concerned with the kinetics of this reaction in the temperature range, 265 ~ ~ ExperimentalReaction rates were determined by following the oxygen pressure at constant volume. A thermistor manometer was used, permitting instantaneous pressure measurements in the range, 1-500 ~, with a precision of better than 0.1% (2).Single crystals of 99.999-~% antimony were used. Small wafers were cleaved normal to the (0001) direction, and this plane accounted for more than 75% of the exposed surfaces, which totaled 0.5 cm ~ per sample. The samples were cleaved in air and transferred directly to an 8 mm tube which was then connected to an adsorption apparatus of the type described earlier (2). A movable tube furnace which maintained the sample temperature to • I~ was then raised into position. Oxygen of spectroscopic purity was used throughout.

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Epitaxial films of GaAs and GaP have been deposited on GaAs, GaP, and Ge substrates by a vapor phase chemical reaction technique. The growth variables, such as source temperature, seed temperature, crystal orientation, surface preparation, and gas flow rate, have been investigated. The optimum conditions for the growth of epitaxial films and the electrical characteristics of these films are reported. GaAs-GaP junctions grown by a solution growth technique (TSM) are abrupt, whereas junctions grown by the vapor phase technique are graded. Detailed measurements of the I-V characteristics and capacitance of GaAs-Ge, GaAs-GaP, and GaP-Ge abrupt heterojunctions are interpreted in terms of Anderson's model. Kinks in the I-V characteristic are explained by discontinuities in the valence and conduction bands.