| 摘要 |
PURPOSE:To enable to effectively obtain the piezoelectric characteristic of a piezoelectric material showing only the coefficient of coupling of vertical effect and a material of an extremely small mechanical quality coefficient Qm, etc. by a method wherein polarization is performed by impressing a DC field within a specific range on a (Pb1-xCax) TiO3 series piezoelectric ceramic having a specific electric resistivity. CONSTITUTION:An Ag electrode is baked on the (Pb1-xCax) TiO3 (where, x= 0.05-0.04) series ceramic whose electric resistivity is 5X10<9>-5X10<11>OMEGA.cm, and the DC field if impressed at 40-100kV/cm in an Si oil controlled at -4-100 deg.C and thus polarized. When said resistivity is less than 5X10<9>(OMEGA.cm), a field of 40kV/cm or more can not be impressed in the temperature range of -40-100 deg.C. On the other hand, when it exceeds 5X10<11>(OMEGA.cm), a sample wherewith the coefficients of coupling Kp and K81 are not confirmed can not be obtained even in impressing the field till insulation breakdown. |
