JPS56155579A - Piezoelectric ceramics - Google Patents

Abstract

PURPOSE:To obtain a piezoelectric porcelain of excellent characteristics by selecting x and y in (Na1-xLix)(Nb1-ySby)O3 so as to be 0.03<=x<=0.14 and 0.001<=y<= 0.03 respectively. CONSTITUTION:Given amounts of Na2CO3, Li2CO3, Nb2O3 and Sb2O3 are together, calcinated for 2-8hr at 800-1,000 deg.C, sintered at 1,130-1,300 deg.C and made to undergo a given polarization. In respect of the crystal grain size and dielectric constant, when x is selected to be 0.14, Y is 0.002<=Y<=0.03<=x<0.10, y is selected to be 0.002<=y<=0.01, while x is 0.01<=x<=0.03. If x<0.03, the polarization treatment voltage is excessively large, so that it is difficult to put it into practical use. If x>0.14, a mixed phase occurs, so that a given piezoelectric characteristic is not presented. If y<0.001 or y>0.03, a uniform porcelain texture can not be obtained in either case. By said composition, a uniform and fine porcelain texture, which has a small crystal grain size, can be obtained, so that it is possible to obtain a material suitable for practical use, which having a large electromechanical bonding coefficient, a small dielectric constant and a large frequency constant and is effective, specially, at more than several MHz.