AVS 46th International Symposium
    Nanometer-scale Science and Technology Division Wednesday Sessions
       Session NS-WeP

Paper NS-WeP1
Tip Passive Chemical Modification and Its Effects on Tribological Measurements

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: X.D. Xiao, The Hong Kong University of Sci. & Tech., China
Authors: X.D. Xiao, The Hong Kong University of Sci. & Tech., China
L.M. Qian, The Hong Kong University of Sci. & Tech., China
Correspondent: Click to Email
In this talk, we present our experimental results on the passive chemical modification process of the silicon nitride AFM tip by OTE/Mica, OTE/SiO@sub 2@, and SiO@sub 2@. The modified tips have different friction and adhesion properties against mica reference samples as compared to their pristine conditions. The resultant tip modification not only depends on the OTE SAM but also on the substrates the OTE SAM is prepared on. In the case of OTE/Mica, the friction of the modified tip against mica reference is much reduced; in the case of OTE/SiO@sub 2@, the friction of the modified tip against mica reference is much increased. It is surprising that bare SiO@sub 2@ can also chemical modify the Si@sub 3@N@sub 4@ tip to increase the friction against mica reference. In the case of OTE modification, it was found that the tips could be cleaned by repetitive friction scans on mica. However, tip modified by SiO@sub 2@ cannot be mechanical cleaned. Moreover, it was also found that humidity and load could also affect the tip chemical modification. Our results here is important for interpreting tribological data since the actual contact chemistry was often over-looked in the AFM experiments in the past.