Ballistic field electron emission from demountable single atom tip

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.