Room Temperature Atomic Force Microscope for Friction Force studies
In order to study Friction phenomena and the isotropy of friction, we have developed dedicated RT AFM microscope and sample holder. The microscope head and the sample holder allowing sample rotation have been developed during the phd thesis of Dr Gregor Fessler.
The microscope is also used in the non contact mode both at fundamental resonnance and higher harmonics
Current topics are studies on C60 island on organic layered crystals and NiO surface.
On the left, a top view of the RTAFM head is presented. The different color present the different area. Red : Sample slider
Green : Cantilever holder
Yellow : Optic fiber
Orange : 4 quadrant photodiode
Dark Blue : Mirors
Light Blue : Switch STM/AFM
On the left, the sample holder developed for isotropy of friction studies. With this holder we are able to rotate the sample in order to study friction along differents surface directions.
Optical detection for cantilever oscillation is achieved with a 4-quadrant photodiode. Light for the optical detection is emitted from a superlum diode equipped with two wavelength, a red (678,5nm) and an infra red (830,6nm), and introduced in UHV via an optical fiber. At the fiber output, in UHV, laser beam is focused with the help of optical lenses. The geometry of the optical path as well as the optical fiber was optimized since the first RTAFM developed in the lab.