An IR investigation of natural and synthetic amesites has been made. The naiural amesite from Chester, Massachusetts, and certain synthetic samples show order in the Al for Si substitution in tetrahedral sheets. Their IR spectra are characterized by sharp absorption bands and vibrations of "isolated" Al tetrahedra. In contrast, the broadening in the absorption bands and the presence of two abso...

The atomic-layer (AL) doping technique in epitaxy has attracted attention as a low-resistive ultrathin semiconductor film as well as a two-dimensional (2-D) carrier transport system. In this paper, we report carrier properties for B AL-doped Si films with suppressed thermal diffusion. B AL-doped Si films were formed on Si(100) by B AL formation followed by Si cap layer deposition in low-energy ...

amygdaloidal, cavity- and fracture-filling zeolites in eocene volcanic rocks from the kuh-e-aradeh of southern kahrizak, in the northernmost part of central iran have been studied in some detail by optical, chemical analysis, sem, and xrd techniques. the zeolites identified, in order of their relative time of formation from early to late, are tetranatrolite, analcime, natrolite, mesolite, stilb...

Atom-probe tomography, transmission electron-microscopy, x-ray diffraction, and firstprinciples calculations were employed to study the (i) compositional evolution of GPII-zones and "!-precipitates, and (ii) solute segregation at !-Al/"!-interfaces in Al-4 wt. % Cu alloys. GPII zones are observed for aging at 438 K for 8 h, whereas higher aging temperatures, 463 K for 8 h and 533 K for 4 h, rev...