The leaching kinetics of lead glasses (25 to 35 mol% PbO-75 to 65 mol% SO,; some with K 2 0 and additions) were determined in 10% acetic acid. Except for a ternary glass (Si0,-PbO-KZO) which had a linear dependence on time, all compositions exhibited a linear dependence on the square root of time for the amount of Pb and K removed. Increasing the SO,: PbO ratio or the AI,O,i content improved the durability whereas adding K,O to a binary PbO-Si02 glass greatly increased the corrosion rate. Activation energies for the rates of Pb and K removal were determined for three compositions and it was deduced that the diffusion of H+ controlled the leaching for binary and 4-component glasses whereas dissolution of the silica network was rate-controlling for the ternary.

Lead concentration profiles were measured in a binary lead silicate glass corroded by acid using ahd a‐backscattering technique. These profiles were characteristic of those predicted for an interdiffusion process and revealed a surface layer deficient in lead. Diffusion coefficients for Pb2+ were calculated, together with values of the total amount of lead removed at the various experimental temperatures and times. Good agreement was found between these data and those previously obtained experimentally. All diffusion coefficient values were high and, correspondingly, activation energy values were low compared with those predicted by the literature for similar glass compositions. This difference was justified from consideration of the leaching process.

Epitaxial thin films of CdTe (1–5 μm) have been grown directly onto (001) InSb substrates or onto intermediate buffer layers of InSb (0.25–0.5 μm) by molecular beam expitaxy. Cross-sectional transmission electron microscopy and high-resolution transmission electron microscopy have been used to characterize the film and interfacial microstructures. Inferences about film quality were also compared with single-crystal x-ray rocking curve data and agreed well. Resulting microstructural features were correlated with various experimental growth parameters and substrate cleaning procedures. Results show that near-perfect CdTe films can be grown on InSb substrates, but film quality is critically dependent upon substrate cleaning. Other factors observed to influence defect formation in the films include growth rate, total growth time, or a change in growth rate during film growth. Extended defects which form include twins, line dislocations, or looplike defects. Lattice imaging has demonstrated the lattice matching across the InSb film/InSb substrate interface, despite the formation of In precipitates during the heat cleaning procedure.