Investigation of longitudinal leaky surface acoustic waves by scanning acoustic force microscopy

We present first measurements on acoustic waves with quasi longitudinal polarization on quartz and lithium tantalate substrates as well as layered systems carried out by a scanning acoustic force microscope (SAFM). Acoustic phase velocities were measured for microscopic areas showing a good agreement with numerical calculations. The influence of the penetration depth of the high velocity pseudo SAWs (HVPSAW) on the SAFM signal formation is discussed.