Ballistic Field Electron Emission from Demountable Single Atom Tip

Abstract

Highly coherent electron emitter is an attractive research subject in nanotechnology. In our group, novel field electron tips of which the entire dimensions are approximately a few nanometers were grown on the apex of the W tip. Owing to thermodynamically stable structures of the nanotips, the equivalent atomic structures were repeatedly reproduced merely by annealing at moderate temperatures. Furthermore, they were found to retrieve the pristine field emission properties. These characteristics, also regarded the "self-reparing function" and "demountable property", respectively, are important for the practical application. In this talk, the structural sample-fabrication procedures, the results of the endurance (destruction-and-regeneration) tests, and the experimental data of the field electron microscopy (FEM), field ion microscopy, and spectroscopy (FES) of the nanotip are shown.. As a result, peculiar emission processes are clarified.

Field electron emission from molybdenum platinum alloy tips

“…In increasing the voltage, the peak intensity also tended to increase. Again, this behavior is consistent with previously reported data on single‐atom electron sources prepared by vacuum deposition and electroplating …”

“…(c)). The observed phenomena are in accordance with previous FIM studies on single‐atom electron sources having a W surface covered with fcc metal (Pd, Pt, Rh, or Ir) . Therefore, we conclude that a nanopyramid terminated with a single atom spontaneously grew independent of the deposition technique.…”

“…In the present work, therefore, we investigated Mo–Pt alloy tips composed of Mo95%–Pt5% and Mo99%–Pt1%, because the critical electric field of Pt evaporation (4.8 V/Å) is sufficiently higher than that required for high‐quality images by FIM. Moreover, because of the inertness of Pt, Pt‐covered tips are demountable, which has been reported for Pt/W alloy tips prepared by vacuum deposition.…”