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The effect of various controlled surface oxidation treatments on photoluminescence excitation spectra of porous silicon for different emission energies was examined. The UV excitation spectra of fresh samples were found to be peaked with a monotonic relation between peak excitation energy and emission energy and to have an onset near 3.3 eV, the direct gap of Si. Aging was observed to unevenly affect the excitation spectra, producing an effective red shift of the peak center. In contrast, anodic oxidation or oxidation byh exposure of the sample to copper ions in solution produced a blue shift of the excitation spectra.

Transmission infrared spectroscopy and secondary ion mass spectrometry examination of porous silicon with luminescent, nonluminescent or metal quenched optical properties indicates the absence of correlation between optical properties and concentration of the chemical elements and bonds present in them. Quenching is associated with a rise in oxygen and fall in carbon and hydrogen levels that are not implicated in the quenching of luminescence.

Deposition on luminescent porous silicon (PS) of different metals is obtained by the immersion of metals in metal ion solution and by evaporation. There is quenching of photoluminescence (PL) on the immersion in ionic solutions of copper, silver and gold, although it is not quenched in other ionic solutions. The PL is also not quenched by the evaporation of 100 angstroms of copper or 110 angstroms of gold. A metallic concentration in the PS layer at a depth of 3000 angstroms is indicated by the results of Auger electron spectroscopy.

Presents a study which investigated the magnetic properties of iron-based superlattices and sandwiches. Consequence of layering processes in superlattices; Details of the preparation of superlattice films; Implication of the similarities in various superlattice series.

Focuses on a study which analyzed crystallographic and electrical properties of Fe/Cr and Cu/Ni superlattices synthesized by e-beam evaporation. Behavior of both properties; Motive for using a modified paracrystalline theory; Way in which crystallographic properties were characterized; Technique used in the measurement of the in-plane electrical resistivity of the films.

Discusses a study which investigated the synthesis and superconducting properties of sandwich and multilayer (super lattice) structures composed of the superconducting alloy and amorphous germanium. Factors that were sputter-deposited on sapphire substrates using a multi-sputter-gun system; Theory used to interpret the observed suppression of the measured resistive superconducting transition temperature; Use of the Rickayzen formula.

Presents a study that measured mechanical properties of composition modulated copper nickel foils. Factors that characterize the mechanical property of materials; Experiment; Result and discussion.

Deals with a study which analyzed the nature of diffusion of copper in p-type porous silicon. Experimental procedures; Metal evaporation in porous silicon; Deposition of aqueous metal ions; Conclusions.