TRANSVERSE SURFACE-ACOUSTIC-WAVE DETECTION BY SCANNING ACOUSTIC FORCEMICROSCOPY

We present a scanning acoustic force microscope (SAFM) for the study o f surface acoustic wave (SAW) phenomena on the submicron lateral scale . Until now, SAWs with in-plane oscillation components could only be s tudied effectively via nonvanishing out-of-plane oscillation contribut ions. By operating the microscope in lateral force mode, where both be nding and torsion of the cantilever are detected, additional amplitude -dependent signals are found, which are due to the interaction with pu rely in-plane polarized surface oscillations. To demonstrate the capab ilities of this type of SAFM, Love waves were studied on the surface o f layers deposited on ST-cut quartz with SAW propagation perpendicular to the crystal X-axis. The phase velocity of the wave as well as the amplitude of a standing wave field was measured and compared to calcul ated values. (C) 1998 American Institute of Physics.