Using room-temperature (RT) site-specific force spectroscopy
F(
Z), we developed a nondestructive single-atom chemical identification method at RT, which is independent of tip, topography (height difference) and chemical coordination, but dependent on atom species, with atomic resolution. We demonstrated atom-by-atom chemical identification of intermixed individual atoms on a Pb/Sn/Si(111)-(√3×√3) alloy surface. Further, we developed a method for RT site-specific force curve measurements
F(
Z) to apply to RT force mapping
F(
X,
Z). From RT site-specific frequency-shift maps Δ
f(
X,
Z) of a Si(111)-(7×7) surface, we deduced normal force maps
FZ(
X,
Z), then potential maps
U(
X,
Z), and finally lateral force map
FX(
X,
Z), successively. Thus, we obtained not only potential maps, but also lateral force maps of the Si(111)-(7×7) surface under noncontact region at RT on an atomic scale.
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