| 摘要 |
PURPOSE:To improve the temperature characteristics by converting a crystal system of Pb(Zr, Ti)O3 into a cubic system and setting the Zr ratio expressed by Zr/(Zr+Ti) at a lower value than the Zr ratio in the phase boundary by a specific mold. CONSTITUTION:PbO is mixed with TiO2 and ZrO2 in a prescribed proportion and the resultant mixture is then formed and burned to provide a ferroelectric porcelain composition expressed by the Pb(Zr, Ti)O3 crystalline substance (hereinafter referred to as PZT). The lattice constants of the obtained PZT are then determined by the X-ray diffractometry. As a result, a phase boundary in which the tetragonal crystal is subjected to the phase transition to a rhombohedral crystal at about 53.0 to 54.0mol.% Zr ratio expressed by Zr/(Zr+Ti) is present. Thereby, when the Zr ratio is set at a lower ratio than that of the phase boundary by 0.5mol.%, the crystal system is the tetragonal system. A great strain is caused by maintaining a proportional relationship to the strong electric field and the durability is excellent. |
