PZTのねじり変形に対するフレクソエレクトリック効果

Abstract

Flexoelectric effect is a phenomenon of electric polarization for strain gradient in material. PZT ceramic is a well-known piezoelectric material but also shows flexoelectricity when it deforms with strain gradient. In this report, flexoelectric coefficient of PZT piezoelectric ceramic for torsional deformation is experimentally measured. In order to obtain strain gradient, torsion is applied to PZT square rod. It is clarified by FEM analysis that almost constant shear strain gradient can be obtain between counterface surfaces on partial side plane of the square rod with torsional deformation. Also when torsional deformation is given to a square rod, electric polarization by piezoelectric effect between the counterface surfaces can be negligible theoretically. Thus the flexoelectric effect can be measured by torsional deformation. Relatively large electric polarization was obtained by experiments.