| 摘要 |
PURPOSE:To improve the electricity-machine energy converting efficiency, by using a lithium borate single crystal to a substrate and at the same time setting the propagating direction of an acoutic wave in a fixed range. CONSTITUTION:An Li2B4O7 single crystal is produced by a draw-up process and then cut with a proper thickness to receive the specular polishing. An electrode film is formed on the mirror surface by a vacuum depositing process. For the propagating direction of a surface acoustic wave, lambda=-30-30 deg., mu=8-32 deg. and theta=-30-30 deg. are set when the Euler angle display is set at (90 deg.+lambda, 90 deg.+mu, 90+theta). The propagating direction corresponds to the cutting direction of the single crystal. In this connection, the cutting angle is set within a range of the prescribed Euler angle. Thus it is possible to set the electricity-machine coupling coefficient K<2> at >=1.5%. |
