Si nanowires (NWs) were doped with large amounts of Li+ ions by an electrochemical insertion method at room temperature. Si NWs with different doping levels were obtained by controlling the discharging/charging of Li/Si NWs cell. The microstructures of Si NWs with different doses of Li+ ions were investigated by high-resolution electron microscopy. The crystalline structure of the Si NWs was destroyed gradually with the increasing of Li+ ion dose. When the Li+ ions were extracted from the amorphous Li-doped Si NWs by the same electrochemical method, local ordering of atoms occurred and recrystallization was observed. The photoluminescence peak and intensity of Li+-doped Si NWs are closely related to the doping dose.
By making use of a novel technique in which TiB 2 particulates are fabricated by an in situ reaction in molten aluminum, we have successfully produced TiB 2 /Al composites. In order to reveal the characteristic of the technique, the mechanism of formation of TiB 2 particulates obtained by this method is studied in this article. Both theoretical and experimental results have shown that the TiB 2 particulates are formed by a diffusion mechanism when the molar fraction of aluminum in the preform is higher than 43.5 pct. In this case, the TiB 2 particulates are generally spherical, and their mean size is less than 2.0 m. On the contrary, the TiB 2 particulates are formed by a solutionprecipitation mechanism when the fraction is lower than 43.5 pct. In this case, the TiB 2 particulates are multifaceted, and the size of most particulates lies between 3.0 and 6.0 m.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.