A technique is described for determining both the elastic surfce wave velocity and its temperature coefficient. The technique can be used on very small samples and is not restricted to any particular class of materials, such as piezoelectrics. It employs an adaptation of the old method of acoustic wave generation with a dc pulse rather than an rf signal applied to a piezoelectric transducer. The generator and receiver transducers are very small chips, approximating point sources, and at the receiver the vertical component of particle velocity is measured as a function of time enabling one to distinguish clearly between various types of surface modes, e.g., Rayleigh wave, pseudosurface wave, Lamb wave, etc. The technique yields absolute surface wave velocities accurate to 0.2% and is readily adaptable to the use of the sing-around technique for measuring relative changes in the sound velocity as small as 1 ppm.
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