| 摘要 |
PURPOSE:To obtain the title composition of piezoelectric porcelain capable of giving high stability, high radial electromechanical coupling coefficient and low specific dielectric constant by limiting a composition range containing Pb, Zn, Nb, Ti, Zr and O and by adding each specified amount of SiO2 and Al2O3 to the composition. CONSTITUTION:The objective composition can be obtained by adding 0.01-0.04wt.% of SiO2 and 0.1-0.5wt.% of Al2O3 to a composition of the formula (such a composition range as to contain the lines connecting the six points represented as (x+y+z)=1, and (a:x)=0.05, (y)=0.5, (z)=0.45, (b:x)=0.1, (y)=0.5, (z)=0.4, (c:x)=0.15, (y)=0.5, (z)=0.35, (d:x)=0.15, (y)=0.4, (z)=0.45, (e:x)=0.1, (y)=0.4, (z)=0.5, (f:x)=0.05, (y)=0.4, (z)=0.05 and to be surrounded by these six points). Using the present composition, piezoelectric porcelain having a radial electromechanical coupling coefficient of as high as >=55% and a specific dielectric constant of as low as <=1600 can be obtained. |
