Effects of Ag content on microstructure, mechanical properties, and electrical conductivity in long time aged Cu-Ti-Ag alloys were investigated. In short time ageing condition, both electrical conductivity and mechanical properties were enhanced by Ag addition. On the other hand, in long time ageing condition, Ag addition showed a faster deterioration of mechanical properties than Ag free CuTi alloys.

The sliding friction and wear performance of Al–Ni–Co–Si quasicrystalline coatings deposited by the high-velocity oxy-fuel technique were investigated under dry sliding conditions. This study indicated that changes in the imposed sliding test conditions modified the friction and wear behavior of quasicrystalline coatings. Qualitative analysis of the contact interface and wear debris were performed with the aim of understanding the role of the third body on the friction and wear processes. The dependence of the coefficient of friction on the sliding velocity and counterpart material was explained by the stick-slip behavior. It was also shown that test conditions favorable for the formation of thick intermediate layers and the densification of the coating subsurface led to low wear rates. Large cylindrical particles, formed by agglomeration of small wear debris, were suggested as a beneficial factor for the reduction of the coefficient of friction.

A class of algebras that describe invariant pseudo-Riemannian connections on SO(3) is shown to comprise Jacobi elliptic algebras arising from the Jacobi elliptic functions

We report successful application of a low-temperature-grown amorphous GaAs (a-GaAs) layer for stabilization of the fundamental transverse mode of InGaAs/GaAs vertical-cavity surface-emitting lasers. The maximum currents maintaining a stable fundamental transverse mode were increased by the antiguide effect of a-GaAs with a high refractive index. For 10-μm- and 15-μm-diameter devices, we attained a stable single-mode emission over a wide range of current. The antiguiding of transverse modes in vertical cavity buried in the high refractive cladding layer was calculated using a two-dimensional beam propagation method.

We report for the first time a successful application of semi-insulating amorphous GaAs layer for surface passivation of index-guided vertical-cavity surface-emitting lasers. The amorphous GaAs layers on ion-beam-etched active region and mirror layers provide a significant improvement, more than 20%, in the threshold current density and differential quantum efficiency. The improvement of these performances is attributed to low defect density at the surface of active layers induced by amorphous GaAs.

Prior to growth of polyoxide, amorphous-Si with a cap of low temperature oxide was annealed to improve the dielectric property of polyoxide. Current-electric field, critical electric field, critical electric field histogram, and Fowler-Nordheim conduction plot were evaluated. The interface of polyoxide and poly-Si was observed with a transmission electron microscope. The annealing of the amorphous-Si prior to oxidation was effective to improve the dielectric property of the polyoxide.

The microstructural degradation of a lattice-matched Ga0.28 In0.72As0.61P0.39/InP heterointerface during atomic intermixing induced by Zn diffusion has been investigated using high-resolution transmission electron microscopy and Auger electron spectroscopy. The localized interfacial stress caused by intermixing appears to create stacking faults in the Ga-mixed InP substrate, and dislocation tangles in the In-mixed GalnAsP layer. The results are attributed to the contrasted effect of tensile and compressive stresses upon the nucleation of partial dislocations from both sides of the intermixed interface. A qualitative model is proposed for the homogeneous nucleation of misfit dislocations from the locally stressed interface.