Sub-Angstrom oscillation amplitude non-contact atomic force microscopy for lateral force gradient measurement


Atabak M., Unverdi O., Özer H. Ö. , Oral A.

APPLIED SURFACE SCIENCE, cilt.256, sa.5, ss.1299-1303, 2009 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 256 Konu: 5
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1016/j.apsusc.2009.10.026
  • Dergi Adı: APPLIED SURFACE SCIENCE
  • Sayfa Sayıları: ss.1299-1303

Özet

We report the first results from novel sub-Angstrom oscillation amplitude non-contact atomic force microscopy developed for lateral force gradient measurements. Quantitative lateral force gradients between a tungsten tip and Si(1 1 1)-(7 x 7) surface can be measured using this microscope. Simultaneous lateral force gradient and scanning tunnelling microscope images of single and multi atomic steps are obtained. In our measurement, tunnel current is used as feedback. The lateral stiffness contrast has been observed to be 2.5 N/mat single atomic step, in contrast to 13 N/m at multi atomic step on Si(1 1 1) surface. We also carried out a series of lateral stiffness-distance spectroscopy. We observed lateral stiffness-distance curves exhibit sharp increase in the stiffness as the sample is approached towards the surface. We usually observed positive stiffness and sometimes going into slightly negative region. (C) 2009 Elsevier B. V. All rights reserved.