Lateral force microscopy using acoustic friction force microscopy

✍ Scribed by Scherer, V.; Arnold, W.; Bhushan, B.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 426 KB
• Volume: 27
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199905/06)27:5/6<578::aid-sia527>3.0.co;2-5

✦ Synopsis

Conventional friction force microscopy (FFM) is widely used for tribological studies of engineering surfaces. It is, however, difficult to separate friction forces resulting from interactions dependent upon interfacial material properties from surface topography-induced lateral forces. We have developed and employed a technique to operate acoustic friction force microscopy (AFFM) by oscillating the sample laterally at megahertz frequencies. The inplane vibrations perpendicular to the longitudinal axis of the cantilever are generated because of lateral forces between the probe tip and the sample. Torsional cantilever vibrations were detected at frequencies of up to 2 MHz. A mean cantilever lift-o † was observed that can be explained by elastohydrodynamic lubrication. The highfrequency torsional vibration amplitude provides information about the lateral forces that can be used to calculate the friction and viscosity of thin surface Ðlms. The AFFM images of metal-particle magnetic tapes were produced, revealing a resolution apparently better than FFM images. Unlike FFM images, AFFM images are independent of the scanning direction, indicating that AFFM images are less sensitive to topography-induced lateral forces. Also, AFFM, allows friction measurements at relative velocities of the order of 1 mm s-1 which is much larger than that obtained in conventional FFM (several lm s-1).