Amorphous lead oxide nanotubes filled partially with single-crystalline lead

Lead oxide nanotubes filled partially with lead were synthesized by a simple thermal evaporation on Si(1 0 0) substrates without any catalysts. The inner diameter, wall thickness, and length of the nanotubes were 10-40 nm, 5-7 nm, and 2-10 μm, respectively. Selected area electron diffraction patterns obtained from these nanotubes revealed that the lead oxide nanotubes were amorphous, but that the lead present inside the nanotubes was single crystalline. During the exposure of an electron beam on these nanotubes, the amorphous lead oxide nanotubes were transformed into single-crystalline lead oxide nanoparticles. A possible formation mechanism of the partially filled nanotubes is suggested in this paper.