Concurrent measurement of adhesive and elastic surface properties with a new modulation technique for scanning force microscopy

Abstract

The combination of two well-established dynamic scanning force microscopy (SFM) modes is incorporated for SFM in combined dynamic X mode or CODY Mode® SFM. A vertical modulation of low frequency and large amplitude is superimposed with a second vertical modulation of high frequency and low amplitude leading to a combination of pulsed force mode SFM, force modulation, and phase sensitive SFM. SFM in the new mode allows the simultaneous mapping of a number of physical surface properties including adhesive force and elasticity over one scan. The new SFM technique is nondestructive and alteration or even destruction of the sample surface is reduced to a minimum. A polymer blend (two homopolymers spin coated on silicon from a tetrahydrofuorane solution of a mixture of poly-2-vinylpyridin and polytertbutylmethacrylate) was used as a sample for comparative measurements between pulsed force mode, force modulation mode and the new SFM mode.