Rimai D, and
Dept. of Phys., Purdue Univ., West Lafayette, IN, USA.
Identification of electrostatic and van der Waals interaction forces between
a micrometer-size sphere and a flat substrate.
Physical Review B-Condensed Matter, vol.53, no.12, 15 March 1996, pp.8065-70.
Publisher: APS through AIP, USA.
The interaction force gradient between a micron-size polystyrene sphere and
an atomically flat highly oriented pyrolytic graphite substrate has been
analyzed as a function of surface-to-surface separation distance z/sub o/
using an oscillating cantilever technique. The interaction force gradient was
found to have two contributions. For z/sub 0/>or=30 nm, an electrostatic
force due to charges trapped on the polystyrene sphere dominates. For z/sub