RELATIONS BETWEEN PIEZOELECTRIC PROPERTIES AND MICROSTRUCTURE IN POLED PIEZOELECTRIC CERAMICS BY APPLIED UNIAXIAL COMPRESSIVE STRESS

Relations among k(p), f(r).d, Q(m) and domain configurations in some piezoelectric ceramics with various Q(m) values were investigated under a polarization process (poling treatment) and depolarization process (applied stress treatment). In those materials, k(p) values in Pb(Zr0.17)(Ti0.33)(Ni1/3Nb2/3)0.5O3 ceramics (low Q(m)) decreased markedly with applied uniaxial compressive stress increase, and became 0.402 from 0.702 (initial k(p) value) by 49 MPa, while 90-degrees and 180-degrees domain patterns revealed by chemical etching were not changed, even by either poling or applied stress treatments. However, k(p) values in (Pb0.625Ca0.375)TiO3 ceramics (high Q(m)) decreased slightly by 49 MPa, and a clear difference in the 90-degrees domain pattern arrangement was observed before and after both poling and applied stress treatments.