ISSN:
1573-2711
Keywords:
scanning tunneling microscope
;
ZDDP
;
graphite
;
structure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract We have studied the adsorption of zinc O,O-diisopropylphosphoro-dithioate (ZDDP) adsorption on graphite at room temperature by STM. Two different structures corresponding respectively to monomer and dimer were observed on this surface although only the dimer was found to exist in the crystalline state. Molecularly resolved images showed that the molecular packing is significantly different from that in the bulk crystalline state. The monomers stand on the substrate to form a regular structure with a unit cell of 4.6 × 6.5 Å2 (β = 110°). The dimers, imaged as elongated protrusions, lie on the substrate to form a regular structure with a unit cell of 6.5 × 9.0 Å2 (β = 125°). The coexistence of both monomer and dimer on graphite reflects competition between the molecule-molecule and molecule-substrate interaction for which the former favors the dimeric form and the latter favors the monomeric form.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00160975
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