AVS 50th International Symposium
    Nanometer Structures Wednesday Sessions
       Session NS-WeA

Paper NS-WeA6
Tribological Investigation of AlNiCo Decagonal Quasicrystals by UHV AFM/STM

Wednesday, November 5, 2003, 3:40 pm, Room 308

Session: Nanotribology
Presenter: J.Y. Park, Lawrence Berkeley National Laboratory
Authors: J.Y. Park, Lawrence Berkeley National Laboratory
D.F. Ogletree, Lawrence Berkeley National Laboratory
M. Salmeron, Lawrence Berkeley National Laboratory
C.J. Jenks, Iowa State University
P.A. Thiel, Iowa State University
Correspondent: Click to Email
Tribological properties of the 10-fold and 2-fold surfaces of AlNiCo decagonal quasicrystals have been investigated in ultra-high vacuum using an atomic force microscope with WC-coated conducting tips. Using stiff cantilevers either tunnel current (STM mode) or force (AFM mode) can be used for feedback. The quasicrystal surfaces were cleaned by sputtering and annealing in UHV and characterized with low enerey electron diffraction (LEED) and Auger electron spectroscopy (AES). Adhesion and friction of decagonal quasicrystal surface were measured by using contact mode AFM. From force-distance measurements we found that tip-sample adhesion on the clean 2-fold surface is two order of magnitude higher than that of the air-oxidized surface. Because of this high adhesion, STM contrast was used to image surface morphology. The effects of in situ oxidation and carbon passivation on quasicrystal friction and adhesion will also be discussed.