Microstructural, electrical properties and temperature stability of resonant frequency in Pb(Ni1/2W1/2)O3-Pb(Mn1/3Nb2/3)O3-Pb(Zr, Ti)O3 ceramics for high-power piezoelectric transformer

Piezoelectric properties of Pb1-aSra(Ni1/2W1/2)(0.02)(Mn1/3Nb2/3)(b)(Zr-x,Ti-y)(1-0.02-b)O-3) ceramics, to which 0.5wt% PbO, 0.3 wt% Fe2O3 and 0.25 wt% CeO2 were added, were investigated at different compositions of a = 0-0,06, b = 0.05-0.09, x = 0.49-0.51, and y = 0.49-0.51. In the ceramics with a constant composition of a = 0 and b = 0.07, mechanical quality factor, coercive field and Curie temperature increased with the decrease in Zr/Ti ratio due to the increase in tetragonality. With the increase of PMN mol% at a = 0, x = 0.51, and y = 0.49 composition, grain size decreased and coercive field increased. At the composition of b = 0.07, x = 0.51, and y = 0.49, the dielectric constant and mechanical quality factor increased while the Curie temperature and coercive field decreased with the amount of Sr. Taking into consideration the dielectric constant of 1,680, the mechanical quality factor of 1,814, and the temperature stability of the resonant frequency TCfr of 88, it was concluded that the ceramics with the composition of a = 0,06, b = 0.07, x = 0.51, and y = 0.49 were best for the high-power piezoelectric transformer application.