Compositional mapping of surfaces in atomic force microscopy by excitation of the second normal mode of the microcantilever

In this letter we study the tip motion of a rectangular microcantilever in the proximity of a surface. The microcantilever has a hemispherical tip attached at its free end. The theoretical simulations led us to propose a method for mapping simultaneously the topography and the chemical composition of a sample surface in noncontact AM‐AFM. The method consists of exciting the first two modes of the microcantilever. The output signal of the first mode is used to image the topography of the sample while the second mode is used to map changes in the composition of the atoms or molecules under the tip. The simulations were performed by modeling the three dimensional microcantilever as a rectangular beam and applying the Newton equation. 25 Then the dynamic deflection function w(x,t) is described by

[1]  Robert W. Stark,et al.  Tapping-mode atomic force microscopy and phase-imaging in higher eigenmodes , 1999 .

[2]  D. Sasaki,et al.  Material anisotropy revealed by phase contrast in intermittent contact atomic force microscopy. , 2002, Physical review letters.

[3]  Joseph A. Turner,et al.  Analysis of the high-frequency response of atomic force microscope cantilevers , 1997 .

[4]  L. Wang.  The role of damping in phase imaging in tapping mode atomic force microscopy , 1999 .

[5]  Robert W. Stark,et al.  Spectroscopy of the anharmonic cantilever oscillations in tapping-mode atomic-force microscopy , 2000 .

[6]  M. Payne,et al.  ROLE OF COVALENT TIP-SURFACE INTERACTIONS IN NONCONTACT ATOMIC FORCE MICROSCOPY ON REACTIVE SURFACES , 1997 .

[7]  Ricardo Garcia,et al.  Tip motion in amplitude modulation (tapping-mode) atomic-force microscopy: Comparison between continuous and point-mass models , 2002 .

[8]  Stephen W. Howell,et al.  Nonlinear dynamics of microcantilevers in tapping mode atomic force microscopy: A comparison between theory and experiment , 2002 .

[9]  L. Nony,et al.  Nonlinear dynamical properties of an oscillating tip–cantilever system in the tapping mode , 1999, physics/0510099.

[10]  Javier Tamayo,et al.  Effects of elastic and inelastic interactions on phase contrast images in tapping-mode scanning force microscopy , 1997 .

[11]  Abdullah Atalar,et al.  Contact imaging in the atomic force microscope using a higher order flexural mode combined with a new sensor , 1996 .

[12]  Á. S. Paulo,et al.  High-resolution imaging of antibodies by tapping-mode atomic force microscopy: attractive and repulsive tip-sample interaction regimes. , 2000, Biophysical journal.

[13]  F. Elmer,et al.  Eigenfrequencies of a rectangular atomic force microscope cantilever in a medium , 1997 .

[14]  Ricardo Garcia,et al.  Phase contrast in tapping-mode scanning force microscopy , 1998 .

[15]  Ricardo Garcia,et al.  Attractive and repulsive tip-sample interaction regimes in tapping-mode atomic force microscopy , 1999 .

[16]  Y. Thomann,et al.  Characterization of the Morphologies and Nanostructures of Blends of Poly(styrene)-block-poly(ethene-co-but-1-ene)-block-poly(styrene) with Isotactic and Atactic Polypropylenes by Tapping-Mode Atomic Force Microscopy , 1998 .

[17]  J. Israelachvili.  Intermolecular and surface forces , 1985 .

[18]  Robert W. Stark,et al.  Fourier transformed atomic force microscopy: tapping mode atomic force microscopy beyond the Hookian approximation , 2000 .

[19]  G. Binnig,et al.  True Atomic Resolution by Atomic Force Microscopy Through Repulsive and Attractive Forces , 1993, Science.

[20]  Ricardo Garcia,et al.  Dynamic atomic force microscopy methods , 2002 .

[21]  J. Loubet,et al.  Phase imaging: Deep or superficial? , 1999 .

[22]  Bharat Bhushan,et al.  Use of phase imaging in atomic force microscopy for measurement of viscoelastic contrast in polymer nanocomposites and molecularly thick lubricant films. , 2003, Ultramicroscopy.

[23]  G. Reiter,et al.  Direct visualization of random crystallization and melting in arrays of nanometer-size polymer crystals. , 2001, Physical review letters.

[24]  J. Sader.  Frequency response of cantilever beams immersed in viscous fluids with applications to the atomic force microscope , 1998 .

[25]  Jason Cleveland,et al.  Energy dissipation in tapping-mode atomic force microscopy , 1998 .

[26]  Hans-Jürgen Butt,et al.  Calculation of thermal noise in atomic force microscopy , 1995 .

[27]  D. Müller,et al.  From images to interactions: high-resolution phase imaging in tapping-mode atomic force microscopy. , 2001, Biophysical journal.