Field emission from one-dimensional single-crystalline NdB6 nanowires

A facile catalysis-free method was utilized to synthesize functional neodymium hexaboride (NdB6) nanowires of single crystal using Nd powders and BCl3 as starting materials. The XRD pattern confirmed that a single phase NdB6 could be obtained. Raman-spectra elucidated the active vibrational modes of the hexaborides. The TEM images clearly showed that the hexaborides were submicron in size with a cubic morphology. The field emission of these one-dimensional NdB6 nanowires showed a low field emission turn-on (5.55 V/μm at a current density of 10 μA/cm2), and high current density with a field enhancement factor of 1037. The emission current density and the electric field followed the Fowler-Nordheim (F-N) relationship. The good performance for field emission was attributed to the single-crystalline structure and the nanowire geometry.