An influence of the electrodes on the frequency of piezoelectric bars

An influence of the vacuum deposited electrodes on the frequency of longitudinally vibrating piezoelectric quartz bars was studied. Both theoretical considerations and measurements show a linear dependence of the frequency on the mass and elastic properties of the electrodes. The influence of the electrodes on the frequency can be eliminated for certain ratio of the length of electrodes to the length of bar (l₁/l₀)₀. A discrepancy between the theoretical and experimental value of this ratio is ascribed to various values of Young's modulus of the bulk metal and a vacuum deposited layer.Devoted to Professor V. Petrílka on his sixty-fifth birthday.