Simultaneous bimodal surface acoustic-wave velocity measurement by scanning acoustic force microscopy

We present scanning acoustic force microscopy (SAFM) mixing experiments of differently polarized surface acoustic waves (SAW) with noncollinear propag ation directions. The phase velocities of the SAWs are measured at a submic ron lateral scale, employing a multimode SAFM that is capable of detecting the wave's normal and in-plane oscillation components. Hereby, the down con version of the surface oscillations into cantilever vibrations due to the n onlinearity of the tip-sample interaction is utilized. The simultaneous det ermination of the phase velocities within a microscopic sample area is demo nstrated for the mixing of Rayleigh and Love waves on the layered system Si O2/ST-cut quartz. (C) 2000 American Institute of Physics. [S0003-6951(00)01 831-3].