| AVS 57th International Symposium & Exhibition | |
| Advanced Surface Engineering | Tuesday Sessions |
| Session SE-TuP |
| Session: | Advanced Surface Engineering Poster Session |
| Presenter: | J.L. Remmert, Universal Technology Corporation |
| Authors: | J.L. Remmert, Universal Technology Corporation J.G. Jones, Air Force Research Laboratory A.A. Voevodin, Air Force Research Laboratory W.P. King, University of Illinois at Urbana-Champaign |
| Correspondent: | Click to Email |
Multifrequency drive capabilities have recently been implemented on the atomic force microscope (AFM) to enhance imaging contrast and retrieve information about the material properties of the sample surface1. Common to each technique is the use of a complex (amplitude-modulated) waveform to oscillate the cantilever tip in proximity to the substrate at two or more of its flexural resonances. Simultaneous measure of the amplitude and phase of the cantilever ac deflection is used to characterize the tip-sample coupling and may, for example, relay mechanical and chemical information through the separation of short- and long- range forces between distinct resonance modes2,3. In this way, bimodal imaging has also advanced magnetic3 and electrostatic4 force mapping with the application of appropriate fields. Related techniques track spatial variations in the contact resonance by evaluating the cantilever response across either a frequency band (band excitation, BE) or at fixed limits bracketing the peak (dual ac resonance tracking, DART). Resonance tracking also reduces crosstalk between the surface topography and frequency-dependent material properties, and has been employed to measure energy dissipation5, as well as for piezoelectric domain characterization6 and local thermal analysis7 with drive signals modulating the local electrical bias and temperature gradient, respectively. This work focuses on the latter approach: the use of dual frequency excitation to resistively heat and actuate an AFM tip for thermomechanical imaging of sample surfaces. Evaluation of the ac deflection at two frequency limits provides the amplitude and phase data required to extract the quality factor (dissipation) by the simple harmonic oscillator model1. The experimental procedure (thermal DART) has been demonstrated along with data post-processing to establish a temperature-dependent study of surface mechanical properties.
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2R. Proksch, Applied Physics Letters 89, 113121 (2006).
3J.W. Li, J.P. Cleveland, and R. Proksch, Applied Physics Letters 94, 163118 (2009).
4R. W. Stark, N. Naujoks, A. Stemmer, Nanotechnology 18, 065502 (2007).
5S. Jesse, S.V. Kalinin, R. Proksch, A.P. Baddorf, and B.J. Rodriguez, Nanotechnology 18, 435503 (2007).
6B. J. Rodriguez, C. Callahan, S. V. Kalinin, and R. Proksch, Nanotechnology 18, 475504 (2007).
7M.P Nikiforov, S. Jesse, A.N. Morozovska, E.A. Eliseev, L.T. Germinario and S.V. Kalinin, Nanotechnology 20, 395709 (2009).