Evaluating LaB₆ (310) nanotip as an ultrafast electron emitter

The crystallographic dependence of electron emission properties from LaB6 single-crystal tips and its importance has been highlighted in several experimental and theoretical studies. Here, we report on the cold field electron emission from LaB₆ nanotips in the $⟨ 310 ⟩$ orientation under static (DC) and laser-assisted conditions for possible use as an ultrafast electron emitter. By changing the voltage and laser intensity, we observe different emission regimes such as the photo-field emission and the multiphoton photoemission. The field electron microscopy patterns change under ultrafast laser illumination and correspond to the region of a high laser field. The emission properties of LaB₆ nanotips in the $⟨ 310 ⟩$ orientation are compared with those of the $⟨ 100 ⟩$ orientation.