Molecular Imaging / Agilent Setup
STM 1 um scanner
AFM 9 um control mode scanner
Environmental cell for controlled atmospheric imaging
Ultra-Low Tunneling at 0.5 pA capacity
Tip Etching and Wax Insulation
While experiments performed on our UHV/LT STM provide great insight into chemical systems, the operating conditions are not practical for “real world” applications. The advantages of our EC-STM instrument is that it works in an ambient environment (i.e. room temp. and 1 atm.), which makes our results more applicable to industrial processing conditions. We are unable to achieve atomic resolution (except for HOPG) using ambient STMs due to the ease with which metal surfaces become contaminated in air (hydrocarbons and water). This problem can be overcome through the use of in situ STM and EC-STM, both of which involve imaging the surface through a protective liquid layer. EC-STM allows for atomic resolution because in an electrochemical cell the voltage can be swept up and down causing any contaminants on the surface to desorb, hence cleaning the surface. In this way we can replicate the level of surface cleanliness that is routinely obtained in the UHV/LT STM. Once the surface is clean it is possible to add molecules to the electrolyte solution and then study the surface arrangement. Using EC-STM, it is also possible to cycle the potential to measure at what voltages certain molecules adsorb and desorb from the surface.