Abstract
Fabrication of sharp and smooth Ag tips is crucial in optical scanning probe microscope experiments. To ensure reproducible tip profiles, the polishing process is fully automated using a closed-loop laminar flow system to deliver the electrolytic solution to moving electrodes mounted on a motorized translational stage. The repetitive translational motion is controlled precisely on the μm scale with a stepper motor and screw-thread mechanism. The automated setup allows reproducible control over the tip profile and improves smoothness and sharpness of tips (radius 27 ± 18 nm), as measured by ultrafast field emission.
Highlights
Active, sharp noble metal tips are essential in experiments such as photon emission at a scanning tunneling microscope (STM) junction,1 ultrafast electron emission,2,3 tip enhanced Raman spectroscopy (TERS),4,5 and superfocusing of propagating plasmons
Au tips are more commonly used because of their inertness in air, but Ag tips are favored over Au tips in vacuum because they are less lossy in the relevant spectral range; and as such, plasmon propagation lengths on Ag are significantly longer
We present a fully automated method for reliably producing such Ag tips, which we verify through the stringent quality test of the stability of their field emission under ultrafast laser irradiation
Summary
Active, sharp noble metal tips are essential in experiments such as photon emission at a scanning tunneling microscope (STM) junction,1 ultrafast electron emission,2,3 tip enhanced Raman spectroscopy (TERS),4,5 and superfocusing of propagating plasmons.6–8 Among noble metals, Ag and Au are the most pertinent because of their low dielectric losses. Published Online: 23 September 2013 Stephen S.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
