Piezoelectric properties of PNW-PMN-PZT ceramics for high power piezoelectric transformer

摘要

Piezoelectric properties of Pb/sub 1-a/Sr/sub a/(Ni/sub 1/2/W/sub 1/2/)/sub 0.02/(Mn/sub 1/3/Nb/sub 2/3/)/sub b/(Kr/sub x/, Ti/sub y/)/sub 1-0.02-b/O/sub 3/ ceramics added to 0.5 wt% PbO, 0.3 wt%Fe/sub 2/O/sub 3/ and 0.25 wt% CeO/sub 2/ were investigated with the variations of a=0-0.06, b=0.05-0.07, x=0.49-0.51, and y=0.49-0.51. Mechanical quality factor, coercive field and Curie temperature with the decrease of Zr/Ti ratio were increased by the increase of tetragonality. According to the increase of PMN mol%, grain size decreased and coercive field increased. Moreover, dielectric constant and mechanical quality factor increased and Curie temperature and coercive field decreased with the increase of the substitution of Sr mol% to Pb sites. Taking into consideration the dielectric constant of 1,680, mechanical quality factor of 1,814, and temperature stability of resonant frequency of TCfr 88 at a=0.06, b=0.07, x=0.51, and y=0.49 composition ceramics, it can be concluded that this composition is the best one for piezoelectric transformer.