Self-assembled composite nano-/micronecklaces with SiO_2 beads in boron strings

摘要

Nano-/micronecklaces with SiO_2 beads in boron strings were synthesized by simply sublimating the desired powders in a sealed quartz tube at high temperature. The boron strings have a rectangular cross section with width varying from 80 to 1000 nm while the SiO_2 beads bear either spindle or spherical shape with a size ranging from 100 nm to 5 μm. The spacing between the SiO_2 beads is uniform in each boron string. Both the boron strings and the SiO_2 beads are amorphous and free of defects. The supersaturated vapors of silicon and oxygen induced the SiO_2 bead formation.