Leaky SAW propagation properties on Li/sub 2/B/sub 4/O/sub 7/ substrates

Theoretical and experimental results have shown the potential usefulness of Li/sub 2/B/sub 4/O/sub 7/ crystals for leaky SAW applications. The existences of orientations with zero TCD have been predicted by the computer analysis and confirmed experimentally for the leaky SAW. Both theoretical and experimental results have shown that the leaky SAW with the zero temperature coefficient of delay (ZTCD) possesses particularly useful cuts such as (/spl lambda/, 90/spl deg/, 70/spl deg/), (0/spl deg/, 75/spl deg/, 42/spl deg/) and (0, 75/spl deg/, 75/spl deg/). The maximum value of k/sup 2/ exists at /spl theta/ of around 60/spl deg/ to 70/spl deg/ on the (/spl lambda/, 90/spl deg/, /spl theta/). k/sup 2/ of the Rayleigh wave is zero at (/spl lambda/, 90/spl deg/, 70/spl deg/), which gives no spurious response for the leaky SAW. Temperature-compensated leaky SAW orientations have been located at both the (0, 75/spl deg/, 75/spl deg/) and (45/spl deg/, 90/spl deg/, 70/spl deg/) with v/sub p/ of 4225 and 3680 m/s and k/sup 2/ of 1.8 and 2.3%, respectively. Further it has been confirmed theoretically and experimentally that a longitudinal leaky SAW with the fast velocity of 6825 m/s also exists around (0/spl deg/, 45/spl deg/, 90/spl deg/).<
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