The synthesis of PrB6 nanowires and nanotubes by the self-catalyzed method

The praseodymium hexaborides (PrB6) nanowires and amorphous PrB6 nanotubes were successfully fabricated through a catalyst-free chemical vapor deposition (CVD) process using Pr powders and BCl3 as starting materials. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) were used to characterize the morphology, composition and structure of the samples. Our results showed that the as-synthesized nanowires were polycrystalline with 10–100 nm in diameter and ~2–10 μm in length. Furthermore, we also obtained PrB6 nanotubes for the first time in our experiment. HRTEM and SAED identified that the PrB6 nanotubes were amorphous in nature. A growth mechanism was proposed for the formation of the PrB6 nanostructure.