Polarization effect in langasite crystals

摘要

The variation of the resonance frequency of piezoelectric resonators subjected to a constant electric field is demonstrated with longitudinal vibrations in La3Ga5SiO14 ( langasite) crystal rods at temperatures between - 60 and + 80 degrees C. For the rods whose longtudinal axis makes angle a with the crystal axis [10 (1) over bar0] in the plane of the axes [10 (1) over bar0] and [ 0001], the change in the frequency is proportional to the field strength and depends on a. For a field of +/- 1.5 x 10(6) V/ m and alpha = 15, the relative change in the frequency is +/- 120 x 10(-6). It is shown that La3Ga5SiO14 crystals offer a set of physical parameters that makes them promising for electrically controlled acoustoelectronic devices and for devices based on nonlinear interaction between acoustic waves.