| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezoelectric ceramic of the non-lead base which can be fired at a lower temperature than a conventional one and has high characteristics. <P>SOLUTION: In a piezoelectric ceramic element, in a composition which is prepared so that elements (Nb<SB>1-z</SB>Ta<SB>z</SB>) of a B site may be more excessive than elements (K<SB>x</SB>Na<SB>1-x</SB>) of an A site in a perovskite compound, and CuO is added at the time of the preparation, whereby a burning temperature is lowered and disadvantages such as volatilization of an alkali component and melting of KNbO<SB>3</SB>are controlled, as a result a sintering property is raised, further, MnO and a rare earth oxide are mixed into a calcined powder in a range at most 2.0(mol%) respectively, thereby electric characteristics such as a piezoelectric constant or the like are raised as compared with a conventional one. Moreover, since decrease of electric characteristics with time is controlled by containing a rare earth, practical electric characteristics become still higher. <P>COPYRIGHT: (C)2009,JPO&INPIT |
