Johnstone, J; Clifford, C (2003) Report on: force repeatability in imaging forces and force vs distance spectroscopy using an atomic force microscope (AFM). NPL Report. COAM 16

Text COAM16.pdf Download (461kB)

Abstract

The issues affecting the force repeatability in imaging forces and force vs distance spectroscopy using an atomic force microscope (AFM) have been assessed. The major contributing factors that affect repeatability are, the drift in the piezo-electric tube scanner position when performing force displacement spectroscopy and the drift in the alignment of the optical lever. These are most acute for very soft cantilevers which heat under the action of absorbed laser radiation. It is recommended that the instrument is left on and aligned for two hours prior to accurate measurements. With care, the repeatability in determining the applied forces may be reduced to approximately 1.6% for a pre-cleaned silicon wafer substrate. When determining polymer modulus, repeatabilities of 6.5% can be achieved by AFM and Hysitron indentation but these are probably limited by the material homogeneity at the nanoscale.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	COAM 16
Subjects:	Nanoscience Nanoscience > Surface and Nanoanalysis
Last Modified:	02 Feb 2018 13:16
URI:	https://eprintspublications.npl.co.uk/id/eprint/2532